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Beyond the Roly-poly Bug Brains as a Model for Invertebrate

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									                                                                                                      NSTA 2004, Atlanta

     Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience
                            Lee G Morris and Melissa K Demetrikopoulos
  Institute for Biomedical Philosophy and the Center for Behavioral Neuroscience, Atlanta, Georgia

Session information
Strand: Hooking Kids on Science
Presentation on April 3, 2004, 17:00 – 17:30, Hilton Atlanta, Clayton Room

Bugs and other invertebrates seem so simple—but display complex behaviors! Explore the importance
of these animals and discover ways to take science into the world.

Bugs and other squishy and crunchy animals (crabs, snails, starfish) often evoke strong reactions in children, both positive
(cool!) and negative (yuck!). We will demonstrate how to capitalize on the fascination that these creatures impart in order
to peak children’s interest in these animals and their behavior, despite the ―yuck‖ factor that is often present. Bugs and
other such critters are easy to find and observe in backyards, school grounds, streams, and even pet stores. Students can
observe and design experiments for commonly known animals such as roly-polies, crickets, snails, lightning bugs, and
hermit crabs. While these sorts of animals (invertebrates) may seem small and inconsequential, they actually make up over
99% of the animals that inhabit the earth, and the diversity and complexity of some of these animals make studying them
more exciting for scientists and non-scientists alike. Invertebrates are used for ecological, biomechanical, physiological,
behavioral, genetic and neurobiological studies, and studies of invertebrates have even led to a number of Nobel Prize
winners. This session will begin to explore best practices of how invertebrates can be used both inside the classroom and in
informal learning situations to teach students a variety of scientific principles, especially those pertaining to behavior and

Targeted Grades Levels
Biology, Upper Elementary-Middle Level; Informal Education
Expansion Activities for Advance Middle, High, and College Levels

Almost every day people see animals. Many of these animals are small, unobtrusive, and therefore
overlooked unless they fly in your face or are served on a dinner plate at an expensive restaurant. Ask
any child to name five animals, and most types of animals that exist in the world are never listed.
However, these animals are more prolific, more diverse, and more fascinating than those first five

These animals are invertebrate animals, animals without backbones. They include that beetle your cat
is trying to eat, the moth fluttering at your screen, the ants invading your kitchen, the slugs crawling
across your sidewalks. They also I include mosquitoes that eat you, and the lobsters that you eat. So
every day you see a fascinating world, without really bothering to see it.

Invertebrate animals are important parts of our everyday lives, yet are not often studied. The study of
such animals in many contexts can spark our interest in science, our understanding of the world and its
biodiversity, and the effects of many species on our existence. We hope to encourage these interests,
understandings, and effects by promoting the use of invertebrates in the classroom in a variety of
manners. One endeavor is the study of the fields of animal behavior and neuroscience, which can
promote further understanding of the world around us, how animals function, react, and cope with that
world, and begin to develop an understanding of our own behavior and responses to that world.

                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
General Objectives
Introduce students and the public to invertebrate animals and invertebrate neuroscience and to promote
    neuroscience literacy
Integration of many scientific fields, including neuroscience, taxonomy, classification, ecology,
    behavior, structure and function (anatomy and physiology), interactions with the environment,
    inquiry skills, observation and communication skills
**A web site connected with this project ( will continue these objectives and
    provide information on hands-on activities that will cover many grade levels and many disciplines,
    and provide links to background information and animal care and procurement information.

Learning Objectives
Generally relate structure and function in organisms
Learn the general anatomy and functions of the nervous system and the role of the nervous system in
Learn that complex behavior and body structures are associated with complex nervous systems
Integrate sensory and nervous systems together – common misconception is that they are two different
Introduction or enhancement of the concept of biodiversity by examining different types (phyla) of
    invertebrate animals; this also promotes understanding of the system of classification of a nimals
Learn details about the animals and their life histories, to associate nervous system structures with
    animal life history traits and behaviors, and to facilitate interspecies comparisons
To provide background and inspiration for designing behavioral experiments and hypothesis
    construction and testing

Be able to list some similarities and differences between invertebrates and vertebrates
Be able to list some similarities and differences between invertebrate and vertebrate nervous systems
Be able to observe and record (communicate) accurately the body plan, movements, and behaviors of
Be able to formulate an educated guess as to the complexity of the nervous system given the
   observations of the complexity of the body plan and behaviors of an organism

Skills Objectives
The skills this project will enhance are observation, communication, inquiry, and prediction.
Observation is important in virtually everything we (humans, not just scientists!) do; it gives us
information (not always visual) about the world around us and our reaction to it. Observation is used
extensively in art, science, the medical field, and many business fields (you would hope your stock
broker is observant enough to notice stock prices decreasing and advise you to sell, for instance).
Communication is also an extremely important skill; we cannot hope to pass on accurate information if
that information is not communicated properly. Inquiry and prediction are also important both in
science as well as the realm outside of science; it promotes individual learning, assessment, and critical
thinking in all endeavors, again, not just in science.

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 2
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
Background and General Information
Just as many people are not familiar with invertebrate animals, neither are they familiar with the
biodiversity of this planet. Biodiversity sustains the individual ecosystems. Variations in the animal
kingdom are often beyond the imagination of even Hollywood writers, but few people know of the
fascinating creatures and tales out there. Knowledge and appreciation of this biodiversity, as well as
our careful exploitation of it to find medicines and products that will enhance our lives, is essential for
the sustainability of this biodiversity. Additionally, many general concepts can be learned and studied
with the knowledge of biodiversity. One concept we promote here is the idea that the more complex a
nervous system is, the more complex an animal must be (in terms of body plan and behaviors).

Body Plans
More complex animals have more complex body plans. For example, the process of cephalization, or
the gradual concentration of sensory structures (in terms of numbers and types) in a single region to
become the ―head‖, is indicative of a more complex form. Sensory structures and limbs also vary in
complexity; eyes, for example, can be simple detectors of light and dark, or highly specialized to see
movement, contrast, outlines, and color. Limbs can be simple (if even present), such as the ―paddle‖
leg of a marine worm, which has as it’s only function a general back-and-forth movement. Conversely,
insect legs are much more complicated with many parts and joints, giving it the freedom to be
accurately moved through space and time.

Animal Behavior
Animal behavior is usually quite fascinating to most humans, even if the only animal observed is the
human one. The study of animal behavior can tell us a lot about the internal (motivations such as
hunger) and external environment the animal lives in. Accurate studies of animal behavior require
astute observations of the animal, it’s movements, and it’s interactions with the environment (including
other animals). These studies can begin to address many of the proximate (how) questions we have
about animals (mechanisms, control by the nervous system) as well as many of the ultimate (why)
questions (function of a behavior, reason for specific adaptations by the animal).

The study of animal behavior is called ethology. Ethologists (scientists who study animal behavior)
begin by watching the animals, describing the movements and interactions that will define a behavior.
These behaviors are also scrutinized to see if there are instances in which certain behaviors occur in a
specific order (sequences), such as a cat always grooming after feeding (see additional resources at
end of handout). The behaviors themselves are also categorized on their level of complexity, which
also reflects the complexity of the nervous system that generated them.

For example, one of the simplest type of behavior is called a taxis (pronounced TAX-iss, the plural is
taxes, pronounced TAX-eez). This is an innate (unlearned) behavior where an animal gradually moves
to an area with preferred characteristics, such as a cockroach moving from an area of light to an area of
dark. Taxes are used often in simple behavioral experiments, particularly with invertebrates: pill bugs
(roly-polies) move from light to dark (negative phototaxis – away from light), from dry to humid
(positive hygrotaxis – towards water).

Learning is a more complex form of behavior, requiring that the nervous system adapt to a stimulus.
A very simple form of learning is called habituation. In habituation, when a stimulus is applied to an
animal, the animal reacts to it; if the stimulus is applied a number of times in close succession, the

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 3
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
animal habituates, or gets used to the stimulus, and the magnitude of the reaction decreases or the
reaction stops all together (extinction).

Communication between two animals is a very complex form of behavior. It requires that a signal with
a specific meaning be sent from one animal, another animal receives that signal AND interprets the
signal properly. There is often innate and learned components to inter-animal communication. Non-
human animal communication can be fascinating, particularly since many animals do not use the same
modes of communication as we do. For example, humans use auditory and visual methods to
communicate, while many animals communicate by smell (for a common vertebrate example, think of
dogs!). Animals also may use means of communication which are relatively foreign to humans. While
we do utilize visual communication systems (think of ―talking with your hands‖), we usually do not
use light itself to communicate. However, this is the primary method of communication between
fireflies (lightning bugs).

Other Behaviors
Invertebrates have a dazzling array of behaviors beyond those we are familiar with in our vertebrae-
centric world. There are also a number of complex behaviors that these animals have, such as that of
thanatosis (than-a-TOE-sis, with the ―th‖ sound like that in the word ―with‖), which is the official
name of the act of ―playing dead‖ or ―playing possum‖. Many bugs will exhibit this complex behavior
that humans don’t have. Many bugs will ―spit‖ when disturbed, lobsters and crabs will voluntarily
detach a walking leg if caught by it, and bees ―dance‖ to communicate to other bees good sources of
food. If possible, these truly different behaviors should be investigated and discussed.

The amount of complexity in an animal’s body plan and in an animal’s behavior can give some
estimation of the complexity of its nervous system. For controlling a complex body, and producing
complex behaviors which often involve complicated movements of the body, the nervous system must
have more cells to receive the appropriate sensory information, more cells to process this information
and make a decision about the resulting behavior (similar to ―thinking‖), and more cells to direct a
complicated movement. Thus, cursory examination and comparison of two very different animals (in
terms of their body plan and behaviors) can result in an informed ―guess‖ as to the complexity of each
animal’s nervous system and be ―smarter‖ than the other.

Animals for Comparisons
Three familiar invertebrate phyla can be used for these observations and subsequent activities: the
annelids (segmented worms), the molluscs (clams, snails, and octopus), and the arthropods (jointed
animals, includes the subphyla of Insecta and Crustacea, which include crabs and lobsters). The
annelids and arthropods are thought to be more closely related as both phyla have segmented bodies
and a ladder-like nervous system consisting of chains of ganglia (clusters of nerve cells) along the
length of the body. Molluscs, on the other hand, have a variety of body plans (just think of the
differences between clams, snails, and octopus), and consequently have different behaviors (clams
don’t do much other than eat, snails will eat, move, and may show hydrotaxis, octopus are highly
mobile, hunt their food, manipulate objects, and protect their eggs). Snails and slugs are most likely the
easiest of the molluscs to procure and study.

In terms of complexity of three well-known organisms, earthworms, snails, and crickets, the
earthworm has the simplest body plan, the least number of observable behaviors, and least complex

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 4
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
nervous system. Snails have a more complex body plan, especially inclusion of a shell, have a few
observable behaviors, and a nervous system that, even though it is differently organized than the
earthworm’s and cricket’s, is still more complex than the earthworm’s. The cricket’s body plan is very
complex, with multiple, jointed limbs and jaws and many visible sensory structures. As such, crickets
have many observable behaviors, including social behaviors, and have a much more complex nervous

More details of animals and their nervous systems can be found in the links under the Resources
section below.

For the following observational and comparison activities, a minimal amount of materials is needed.
Materials for the behavioral assays or the experiments the students design will depend on the
        Animals – ―feeder‖ crickets and pond snails can usually be bought in a local pet store, land
                snails can be obtained from a biological supply company; an alternative is to collect
                them yourself
        Containers to keep animals – small aquarium with tops, either glass or plastic, work well. Large
                plastic food storage containers also work. These containers should have shelters, food,
                and water sources in them for the animals. (The water source for the terrestrial animals
                can be a dampened paper towel.)
        Containers to observe the animals – these containers should be large enough for the animal to
                move around in, with clear sides for observation. If the containers you keep the animals
                in have only one animal per container, then a separate observation container is not
        Food and shelter for the animals –food will depend on the animal used; shelter can often be a
                small box, pieces of cardboard egg carton or even a folded paper towel
        Refrigerator to ―anaesthetize‖ the animals – this would be mainly for arthropods; as arthropods
                (crickets) can be very active, it may be necessary to slow them down or ―put them to
                sleep‖ to observe the details of their bodies closely. 15 minutes in the refrigerator (not
                freezer) should slow them down enough for observation.
        Magnifying glass or dissecting stereomicroscope – for close observation of the animals’ bodies
        Paper towels – for clean up, shelter, and water sources (damped) for terrestrial animals
        Timer or stopwatch for timing habituation responses or to prompt for the next observation
                when sequencing an animal’s behavior
        Small pipette or straw

      Body plan:
             Look for the presence/absence of sensory structures
             Look for presence of cephalization
             Look for the presence complex body structures like complicated joints or very
              specialized structures.
             Observe a solitary animal for one minute. What does it do? How many different
              behaviors can be distinguished?

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 5
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
               Observe two animals in the same ―space‖. Make sure the snails are placed in close
                proximity to each other. What are their behaviors? Are these behaviors different than
                those of the single animal? Do the two animals interact?

     Compare between the body plans of the two different species. Does one seem to be more
        complex than the other?
     Compare the behaviors of the solitary animals. Does one of the types of animal have a larger
        number of behaviors than the other? Does one type of animal have more complex behavior
        than the other?

Behavioral Assays:
       Taxes – Phototaxis and Hygrotaxis
   The basic roly-poly can be used to assay phototaxis (light) and hygrotaxis (humidity). These
   animals prefer dark, humid conditions, so will tend to gather in dark, humid places. Containers set
   up with a dark side and a light side should show the animals aggregating on the dark side, while
   containers set up to be damp at one end and dry at the other should show the animals aggregating
   on the damp side. One interesting behavioral note: some of the roly-polies may actually seem to
   prefer the light side. This can happen if the animal has a specific parasite (an acanthocephalan
   worm, the eggs of which are usually inadvertently eaten by the roly-poly). This parasite lodges in
   the body of the roly-poly, and interferes with the normal functioning of the animal so that the roly-
   poly will orient towards the light. This is necessary for the parasite, as the next host in its life cycle
   typically is a bird. If the roly-poly comes out into the light, it is more likely to be seen and eaten by
   the bird. The parasite then moves on to the next stage of its life.

       Sensory responses – Vision and Detection of Air Movement
   Crickets respond quickly to various stimuli. Crickets are visual animals, as can be determined by
   the large eyes, and are very sensitive to moving air, which the two large cerci on either side of its
   abdomen sense. Avoidance responses (moving away from the stimulus or jumping) can be elicited
   from crickets by either type of stimulus. To test the visual response, a good, repeatable stimulus is
   to have a small object with a piece of thread tied to it in the cricket’s immediate environment. A
   measured pull on the thread (for example, one centimeter each time) when the cricket is nearby
   (within two inches from the object) should cause an avoidance response in the cricket. To test the
   cerci, direct a puff of air from a small pipette towards the animal’s rear end (a straw would work
   well, but care most be taken not to give too much of a ―puff‖). The animal should move away from
   the air puff.

       Sensory responses – Test for Habituation
   Habituation can be easily tested with snails or the ubiquitous roly-poly. With the snail, a slight puff
   of air (or water) aimed at its tail or a tentacle will cause the animal to withdraw the stimulated body
   part. At the puff, the student should start a stopwatch (or look at a clock/watch with a second
   hand). When the animal have FULLY re-extended the tail or tentacle (recovered from the
   stimulus), the time should be noted. Repeat the process. Subsequent stimuli should cause a
   response that takes the animal less time to recover from. The snail may actually not pull in the tail
   or tentacle as far, either, in these subsequent stimuli (if the snail is on glass, students may be able to
   measure that distance moved from the opposite side of the glass from the snail, as that should not
   re-disturb the snail). Repeating the stimulus may cause the response to disappear completely. The

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 6
                                                                                                  Morris and Demetrikopoulos
                                                                                           Institute for Biomedical Philosophy
    students can then plot their results: the length of time the body part was withdrawn or the distance
    the body part was withdrawn versus the number of stimuli given. A very similar experiment can be
    done with the roly-poly. Lightly touching the roly-ploy (in the same place each time) will cause the
    animal to roll up. After it unrolls, subsequent stimuli can be given. The length of time the animal
    stays rolled up should decrease when the number of stimuli given is increased.

        Students can design their own experiments with a little guidance. Experiments can and should
build on the observations the students made on the body plans and behaviors of the animals. They can
1) examine sensory responses and taxes, 2) design an experiment with the animals they have already
observed to test predictions of differences in behaviors, or 3) predict behavioral complexity of a new
animal based on the observation of the body plan of the new animal and comparing it to that of the
studied animals.
                                   (see for examples)

Comparison Chart for Snail and Cricket Body Plans and Behaviors
This chart is a reference for the teachers using snails and cricket in the classroom. It is not comprehensive, but should give
ideas for characteristics the students should look for.
Characteristics          Snail                                     Cricket
Head                     yes, head-region                          yes, separate, movable head
Eyes                     very small to none                        large, compound
Antennae                 short tentacles                           long antennae
Smell/taste              on tentacles                              on hairs on legs, head
Touch                    receptors in skin                         hairs on body, cercal system, receptors in skin
Ears                     probably none – pick up                   tympanal organ on front leg, responses to noises
                         ground or water vibrations?               – ambient and other crickets
Makes noise              no                                        chirp by rubbing wings together (adult stage),
                                                                   used to communicate with other crickets
Detect wind              possibly with moist skin                  cercal system (two hair-like structures on tail-
                                                                   end of animal
Appendages               no                                        6 legs (the 2 hind legs powerful), 2 antennae, 2
(legs)                                                             cerce, ovipositor in females
Locomotion               crawl                                     walk, jump, fly (adult stage)
Feeding                  rasp-like ―tongue‖ called                 large, moveable jaws for chewing
Escape                   withdraw into shell                       move away quickly, jump
Speed of                 mainly slow                               quick
Social interactions not much                                       territoriality, aggression, courtship

Suggested Expansion Activities
For motivated middle school students, high school and college students:

Students can take longer observations of the behaviors of the animals. They can actively build an
―ethogram‖ and look for sequences of behaviors that seem to go together. They can thus investigate
more complex behaviors and inter-animal interactions including aggression and courtship. They can
also expand the species comparisons, for example, adding another invertebrate and maybe a small
vertebrate (frog or toad). Increasing the number of species should further reinforce the idea that a

                  Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                           7
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
complex and larger brain and nervous system is needed for a more complex body plan and complex

More details on the background of this project and other activities and references can be found at:, specifically
This site also has general information on invertebrates, neuroscience, invertebrate neuroscience,
educational units on those subjects, and links to many more relevant sites for this project.

The ―Neuroscience for Kids‖ site at the University of Washington is replete with neuroscience
information and activities.
This second site has general information on invertebrate nervous systems.

The Tree of Life website – descriptions and classifications for all animals.

See this site at the University of Arizona’s Center for Insect Science has many lesson plans on using
insects in the elementary classroom:
See this site: for basic information on crickets.
See this site: for cricket rearing information.

A site that expresses a ―shameless promotion of insect appreciation‖ (information on insects):

Two sites for experiments with crickets. The second is more for upper-level high school or college

The students should correctly determine that one species has a more complex body plan. A more
complex body plan is usually one that has a larger number of sensory structures, complicated body
structures, strong cephalization. For example, in terms of sensory structures, the cricket has prominent,
compound eyes, antennae, and cerci, and closer observation shows body hairs and the tympanal organ
on the foreleg. The snail, on the other hand, will have very small, simple eyes, if visible at all, and
tentacles. Complicated body structures in the cricket are the large number (six) of legs with many
joints each, a moveable head, and complicated jaws, while the snail has only the tentacles and the
shell. The cricket also shows very distinct cephalization, with a separate, moveable head, while the
snail has a more generalized head ―region‖.

The student should correctly determine that one of the species has a larger behavioral repertoire.
During the one minute observation period, the snail will likely sit still, locomote, withdraw into the
shell, and possibly (with the right conditions and available food) feed. Crickets will be more active,
moving around the space, moving their antennae around, and changing directions. When paired with a
conspecific, crickets are much more likely to interact, at the very least be aware of the other animal’s
presence, indicated by orientation towards the other animal, locomotion towards the other animal and

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 8
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
possibly using its antennae to ―feel‖ the other animal. Snails are more likely to seem to not notice each
other, exhibiting little or no orientation or locomotion towards the other animal.

The species with the more complex body plan will most likely be the species that exhibits a larger
behavior repertoire. In the examples used here, the cricket has the more complex body plan and
behavior than the snail. The increased complexity in body plan and behavior should indicate to the
student that the nervous system would consequently have to be more complex. In fact, this is the case
in the cricket – snail comparison. Details of rubrics at

Integrating Across the Curriculum
These activities can be easily adapted and expanded to be integrated into other disciplines. The detailed
descriptions of the animals and their behaviors can be subjects of essays, stories, and other written
assignments to bring in writing and other language arts; communication of observations is very
important in the field of science, so incorporation of writing is strongly encouraged. To make the
assignment less of a ―task‖, students can be directed to write a short, detailed description of an animal
and its behaviors without using the name of the animal (or other extreme identifying traits). The
description can then be read aloud to a group or the whole class, and the students asked to guess what
animal it is. This would encourage very detailed observations and carefully written descriptions on the
part of the students for them to be successful in communicating to others the identity of the organism.

Activities can also be easily designed to include math skills. Simple habituation experiments lend
themselves well to charting and graphing data; in habituation, the more times a stimulus is presented to
an animal, the less the animals responds to that stimulus. In the case of touching roly-polies, the first
touch elicits the ―rolling-up‖ behavior that can last a long time (minutes). In subsequent pokes, the
roly-polies will roll up, but stay in this position for shorter amounts of time. The students can plot both
the number of the stimulus (poke) versus the duration of the rolling-up behavior (there will be an
inverse relationship, so that the larger the number of pokes, the shorter the duration of the behavior).
They can also test multiple animals, and compare the number of stimuli needed for the rolling-up
behavior to go to extinction. Additionally, if the animals have been housed in different conditions
(light versus dark), the responses of the two groups of animals can be compared.

National Science Education Content Standards
The study of invertebrates, their nervous systems and behaviors lend themselves well to meeting the
national standards for science education for students in biology. National Science Content Standard A
(Science as Inquiry) requires that all grade levels develop abilities necessary to do scientific inquiry
and understanding about scientific inquiry. The extensive observations and comparisons necessary to
perform these activities well help students develop inquiry skills.

Nation Science Content Standard C (Life Science) requires that students in grades kindergarten
through four develop an understanding of characteristics of organisms and life cycles of organisms.
The structured observation required to compare the complexity of body plans of the organisms can
strengthen students’ observation skills of the characteristics of organisms, and depending on the types
and life stage of the organisms used in these activities, life cycles may be addressed as well. The
standards for grades five through eight include the understanding of the structure and function of living
things, the regulation and behavior of living things, and the diversity and adaptations of organisms,
which can all be addressed in the observations of animals’ body plans and behaviors and comparisons
of organisms from different Classes or Phyla. The standards for grades nine through twelve include the
behavior of organisms and organization in living systems. Organization in living systems can be seen

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 9
                                                                                                Morris and Demetrikopoulos
                                                                                         Institute for Biomedical Philosophy
in the similarities and differences of organisms across Phyla, as well as the recognition of
organizational levels of behaviors of the organisms. These activities also apply to some degree to
National Science Content Standards F (Science in Personal and Social Perspectives) and G (History
and Nature of Science)(see charts below).

The information in this session, packet, and related website provides scientific-based content, using an invertebrate model,
which applies to the National Standards. These resources also suggest ways to utilize this model in student based inquiry
projects appropriate in both formal and informal science settings.

National Standards

Science as Inquiry
As a result of activities in grades K-4, all students should develop
*        Abilities necessary to do scientific inquiry
*        Understanding about scientific inquiry

As a result of activities in grades 5-8, all students should develop
*        Abilities necessary to do scientific inquiry
*        Understandings about scientific inquiry

As a result of activities in grades 9-12, all students should develop
*        Abilities necessary to do scientific inquiry
*        Understandings about scientific inquiry

Life Science
As a result of activities in grades K-4, all students should develop understanding of
*        The characteristics of organisms
*        Life cycles of organisms
*        Organisms and environments

As a result of activities in grades 5-8, all students should develop understanding of
*        Structure and function in living systems
*        Regulation and behavior
*        Diversity and adaptations of organisms

As a result of activities in grades 9-12, all students should develop understanding of
*        Matter, energy, and organization in living systems
*        Behavior of organisms

Science in Personal and Social Perspectives
As a result of activities in grades K-4, all students should develop understanding of
*        Characteristics and changes in populations
*        Types of resources
*        Changes in environments

As a result of activities in grades 5-8, all students should develop understanding of
*        Science and technology in society

As a result of activities in grades 9-12, all students should develop understanding of
*        Personal and community health**
*        Science and technology in local, national, and global challenges**
**[These two can be addressed by using or discussing pest and parasitic species of invertebrates]

                 Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                     10
                                                                                                Morris and Demetrikopoulos
                                                                                         Institute for Biomedical Philosophy
History and Nature of Science
As a result of activities in grades K-4, all students should develop understanding of
*        Science as a human endeavor

As a result of activities in grades 5-8, all students should develop understanding of
*        Science as a human endeavor
*        Nature of science

As a result of activities in grades 9-12, all students should develop understanding of
*        Science as a human endeavor
*        Nature of scientific knowledge

National Science Education Teaching Standards
These activities address many aspects of the National Teaching Standards. These activities are very
adaptable to all student levels and backgrounds (Teaching Standard A), particularly since the use of
animals seen in every day settings can be used, so the students can develop observation and description
skills with familiar organisms and not organisms that can only be studied on field trips to the zoo or
aquarium (Teaching Standard D). This may encourage students to examine the natural world outside
the classroom and thus take scientific observation and inquiry out of the classroom and into their lives.
Also, the detailed descriptions of the animals and their behaviors can be brought across disciplines,
integrating writing and language skills with the science skills. The students can be encouraged to
design their own ―experiments‖, which will allow teachers to focus and support science inquiry while
interacting with the students, and allow the students to become responsible for their own learning
(Teaching Standard B). Some activities, such as the short written description of an un-named animal
and its behaviors by the students that the other students guess the identity of the described animal can
guide self-assessment in the students (Teaching Standard C). Finally, many of these activities require
that the students collaborate together to gather data (one student to time the habituation responses
while another to actually monitor the animal). The students can pursue individual ideas or group ideas
in developing and performing the ―experiments‖ (Teaching Standard E).

                Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                     11
                                                                                     Morris and Demetrikopoulos
                                                                              Institute for Biomedical Philosophy

                  Acknowledgements: The original project that this stems from, ―Do
                  Bugs Have Brains‖, was developed by the first author (Lee G
                  Morris, Institute for Biomedical Philosophy) and Nadja Spitzer,
                  Department of Biology, Georgia State University. That project was
                  partially supported by the Center for Behavioral Neuroscience, STC
                  Program, NSF Agreement # IBN-9876754; NIDA SEDAPA #R25
                  DA 13522 to Andrea Zardetto-Smith at University of Nebraska at
                  Omaha for Brains Rule! Neuroscience Expositions; and the FIRST
                  program, Emory University & Atlanta University Center, MORE
                  Programs Division NIGMS #1K12GM00680.

                  Support for this session is partially provided by the Institute for
                  Biomedical Philosophy, the Center for Behavioral Neuroscience and
                  the Society for Neuroscience.

Contact information for authors:

Lee G Morris,,

Melissa K Demetrikopoulos,,

The Center for Behavioral Neuroscience

  The Institute for Biomedical Philosophy
  promotes intergenerational learning in
            the arts and sciences.

         Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 12
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
Additional Resources

Anatomy of the Cricket and the Snail
         External Anatomy of a Cricket                             External Anatomy of a Snail

The structures shown above are not all the structures that can be viewed on these animals, and may
vary depending on the life stage or species used. For example, the wings on a full grown adult cricket
will run nearly the length of the abdomen, and the organism may use these full-developed wings to
chirp. In snails, the eye will vary by species, with some snails having the eye at the end of a tentacle,
like in the diagram above; other snails will have it at the base of the tentacle on the head. The number
of tentacles may vary (one or two pair). From this view, the mouth of the snail cannot be seen (it is
under the animal), and the operculum (round piece of shell that covers the opening of the spiral shell
when the animal withdraws) can often be hidden from a lot of angles. Some snails may also have a
siphon (unpaired) projecting from the anterior portion of the shell.

Comparisons of Animal Body Plans and Behaviors Between and Within Phyla
Depending on availability of specimens, multiple comparisons can be made. If live specimens are not
available, preserved (or stuffed/freshly dead) specimens can be examined to compare the complexity of
the body plans. If the specimens are familiar ones, comparisons can be made of the known behaviors.
Some interesting comparisons may include:

Specimens from the same Phyla but different Classes
       Phylum Mollusca, Classes Bivalvia (clams or other bivalves), Gastropoda (snails), and
       Cephalopoda (squid and octopus)
       Phylum Chordata, Subphylum Vertebrata, Classes Amphibia (frogs or salamanders), Aves
       (birds), and Mammalia (small rodents such as hamsters or gerbils)
Specimens from different Phyla
       Phyla Annelida (earthworms), Arthropoda (crickets, ants), Mollusca (snails), and Chordata
       (frogs)          ** see table below **
Specimens from specific ecosystems, such as organisms from marine or freshwater ecosystems
Specimens from different Phyla with similar adaptations/behaviors, such as organisms that fly
(dragonflies, birds, and bats) or swim (jellyfish, waterbugs, squid, and fish).

              Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 13
                                                                                            Morris and Demetrikopoulos
                                                                                     Institute for Biomedical Philosophy

Characteristics      Earthworm              Snails                Crickets                    Frogs
Head                 yes, head-region       yes, head-region      yes, separate,              yes
                                                                  movable head
Eyes                 none                   very small to         large, compound             yes, large
Antennae             none                   short tentacles       long antennae               none
Smell/taste          few on head and        on tentacles          on hairs on legs,           some on tongue
organs               ―neck‖ region                                head
Touch                receptors in skin      receptors in skin     hairs on body, cercal       receptors on skin
                                                                  system, receptors in
Ears                 none, but senses       probably none –       tympanal organ on           yes, tympanic
                     ground                 pick up ground        front leg, responses        membranes on sides
                     vibrations             or water              to environmental            of head, responses to
                                            vibrations?           noises and other            environmental noises
                                                                  crickets                    and other frogs
Makes noise          no                     no                    chirp by rubbing            croaks and other
                                                                  wings together (adult       calls, used to
                                                                  stage), used to             communicate with
                                                                  communicate with            other frogs
                                                                  other crickets
Detect wind          probably with          probably with         cercal system (two          probably with skin
                     skin                   moist skin            hair-like structures
                                                                  on tail-end of animal
Appendages           none                   none                  6 legs (the 2 hind          4 legs, hind legs
(legs)                                                            legs powerful), 2           powerful
                                                                  antennae, 2 cerce,
                                                                  ovipositor in females
Locomotion           crawl, burrow          crawl                 walk, jump, fly             walk, jump
                                                                  (adult stage)
Feeding              eats decayed bits      rasp-like             large, moveable jaws        large mouth, long,
                     of matter in the       ―tongue‖ called       for chewing, eats           sticky tongue, catches
                     soil                   radula, eats          plant matter                live insects
                                            algae by
Escape               burrow into            withdraw into         move away quickly,          camouflage, jump
                     ground                 shell                 jump
Speed of             slow                   slow                  quick                       quick
Social               not much – for         not much– for         territoriality,       territoriality,
interactions         reproductive           reproductive          aggression, courtship aggression, courtship
                     purposes only          purposes only
Brain and            Very small             Very small            ―Brain‖, ventral            Brain with dorsal
nervous system       ―brain‖, chain of      ―brain‖, ganglia      nerve cord with             spinal cord
                     ganglia down           distributed in        ganglia
                     ventral nerve          body regions

               Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                  14
                                                                                          Morris and Demetrikopoulos
                                                                                   Institute for Biomedical Philosophy
Behavioral Studies
Catalog of Behaviors
Detailed studies of behaviors can be undertaken in relatively short amounts of time. For a given
organism, a catalog of recognizable behaviors (ethogram) can be constructed, where the students
observe, describe, and name with some detail a number of behaviors. If there are many behaviors, or if
the behaviors occur rapidly, it is often useful to have behavioral codes for each behavior. The table
below shows an ethogram for a cat. The ethogram not complete, in that there are many behaviors that
are not listed, but it is still relatively comprehensive. The number of behaviors that are listed in the
ethogram often depends on the number of behaviors observed; if the cat has not been observed batting
a ball with a paw, the behavior might not be listed. As such, ethograms are often growing and changing
with continued observation of the organism.

Ethogram of Cat
   Name of Behavior            Behavioral Code          Description of Behavior
   Eat                                E                 Using mouth to pick up and chew food
   Groom                              G                 Rhythmic movements of the paw, head, and tongue,
                                                        with the tongue licking the paw, and then the paw
                                                        rubbing a portion of the head
   Jump                                  J              Movement of the body upwards due to synchronous
                                                        pushing of the hind legs on the ground
   Lying Down                            L              Body of the cat is not being held upright
   Meow                                  M              Noise consisting of one or more distinct ―syllables‖ ,
                                                        uses mouth to make noise
   Purr                                  P              Rumbling noise heard in throat area; does not use
   Rub Furniture                        RF              Walking while rubbing head, body, and/or tail along
   Rub Legs of Human                    RL              Walking while rubbing head, body, and/or tail along
                                                        the legs of a human
   Running                             Run              Rhythmic moving of the four legs, front ones and
                                                        hind ones moving in synchrony, to progress the
                                                        animal forward; faster than a walk
   Scratch                              Scr             Rhythmic movement of hind leg directs towards
                                                        another part of the body
   Sitting                               Si             Back end of the animal is resting on the ground, but
                                                        the front end is not
   Sleep                                Sl              State of consciousness lasting more than one minute
   Sniffing                             Sn              Nose held close to an object; nostrils seen flaring or
                                                        ribs expand often indicating quick breaths
   Walk                                  W              Rhythmic moving of the four legs in alternation to
                                                        progress the animal forward

Sequential Analysis
After the ethogram is constructed (or during another class period), the students can sequence the
behaviors, or write down the behaviors in the order which the organism performs them. Often,
ethologists will note the behavior that is occurring at set intervals (for example, every 5 seconds, or
every 30 seconds). Slow animals (like snails) will require longer intervals.

              Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 15
                                                                                         Morris and Demetrikopoulos
                                                                                  Institute for Biomedical Philosophy

Sequence of Behaviors in a Cat (recorded every 30 seconds)
   Time (minutes)         Behavior              Time (minutes)                       Behavior
   :00                    walk                  5:30                                 eat
   :30                    walk                  6:00                                 eat
   1:00                   run                   6:30                                 groom
   1:30                   rub legs of human     7:00                                 groom
   2:00                   meow                  7:30                                 walk
   2:30                   meow                  8:00                                 groom
   3:00                   rub legs of human     8:30                                 walk
   3:30                   meow                  9:00                                 groom
   4:00                   meow                  9:30                                 purr
   4:30                   eat                   10:00                                sleep
   5:00                   eat                   10:30                                sleep

Organization of Behaviors
As you can probably tell, it’s feeding time for the cat at the beginning of this sequence of behaviors.
The cat feeds, grooms, and eventually goes to sleep. This particular pattern of behaviors may be
considered ―stereotypical‖, that is, they vary little in the order in which they are performed on any
given day. For example, the likelihood of grooming following eating is very high. If the animal the
students are observing is an active one, the students can observe it for a short amount of time every
day. They may be able to pick out behaviors that the animal is likely to be doing during the observation
time, and if certain behaviors follow other behaviors.

If the students are comparing two different organisms for behavioral complexity, comparisons of the
ethograms and the top three behaviors observed for each animal can be compared. Animals with more
complex behaviors will have longer ethograms, and are often observed behaving differently more often
during daily observations.

             Beyond the Roly-poly: Bug Brains as a Model for Invertebrate Neuroscience Activities                 16

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