Animal Behavior Lab
Introduction:
Ethology is the study of animal behavior. This involves observing an organism’s behaviors, interpreting what is observed, and
research different organisms. Ethologists study and observe an
organism’s reaction to the environment around them.
Biotic and abiotic factors are limiting factors that control the
maximum size of a given population. Favorable conditions are
desired by an organism of its home environment. Because of
this, an animal must search for the environment to fit its
structure and lifestyle. This is called habitat selection.
An animal can display many different types of behaviors, two
being taxis and kinesis. Taxis behaviors are deliberate
movements toward or away from a stimulus. Kinesis is a random movement that is not
oriented toward or away from a stimulus. Taxis behaviors are exemplary of the physiological
needs of an organism. Other behaviors are agonistic (aggressive or submissive actions
toward another organism) and mating behaviors.
In today's lab we will examine the movement behavior of "Pill Bugs"
Materials:
The following materials will be needed to complete the experiment: 10 pill bugs, 2 animal
behavior petri dishes, 2 pieces of filter paper, 1 camel’s hair brush.
Procedure:
1. First, place the 10 pill bugs and some "bedding" into a petri dish and take general
observations of their movement and interactions for at least 10 minutes. Make a list of the
data you have collected. Sketch a Pill bug and try to label the "head" and the "tail" of the
bug. Notice where they go, how they interact and anything else you may see. Do Not, prod
or push them around. We want to observe their "natural" behavior.
Place a pillbug in a petri dish under the dissecting scope and make a Pill Bug Sketch.
Do you have a male or female pillbug? ________
How can you tell? (Answer is in Pillbug Natural
History at the end of this Lab)
Observe several pill bugs to determine whether or
not they have an orderly structure that is consistent
across all observed bugs.
Example Data: General Observations
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The larger pill bugs climbed over the smaller sized ones.
Movement mostly around edges of tray.
Legs move in quick, fluid motion.
Use antenna to sense closeness of other isopods.
When flipped on back side, will kick off from ground or other pill bugs to flip back
over.
Seven pairs of legs.
In this experiment, you will see the pill bug’s preference for a wet or dry environment. Place
two pieces of filter paper in the choice chambers you have (see below). Make one filter
paper wet, but not saturated and leave the other dry. With a paint brush or a pencil eraser,
carefully place 5 pill bugs on one paper and five on the other.
Every 30 seconds count and record the number of pill bugs in each chamber. Do this for 10
minutes, even if the bugs aren't moving.
Pill bugs are crustaceans, and they respire through gills. Because of this characteristic,
which situation would you predict? __________________________
Graph the number of pill bugs in the wet and dry chambers: Follow the graphing
instructions below:
Graphing Instructions: Remember to graph the independent variable on the horizontal (X)
axis and the dependent variable on the vertical (Y) axis. Your graph should have 2 lines:
one representing the pillbugs in the moist chamber and another representing the pillbugs in
the dry chamber. You can draw the lines in different colors or distinguish them by using
different symbols for the points on the graph or the lines themselves (ex. solid vs. dashed).
This will be a "dot-to-dot" graph. Be sure to include a legend describing which line
represents which chamber.
Interpreting Your Graph: If the lines diverge from each other (go away from each other) at
some point, then your pillbugs are likely showing a preference for the chamber represented
by the line that is mostly going up. If the lines converge on one another (criss-cross a lot or
are on top of each other a lot), then the pillbugs are not showing a preference for either
chamber. Remember, that in science, no result is wrong. It is what it is. If this experiment is
done in reality and the pillbugs don't behave as expected, it may be due to the fact that they
are stressed from being manipulated for example.
Further thought: You could design your own experiment, using the same chambers you just
made, by thinking of another set of variables to test. You could try varying pH, light and
dark, warm and cool or any of many other tests. You may even want to use more than two
petri dishes. Think about how you could test multiple variables and leave a control, food
preferences for example? Consult your Lab instructor for ideas.
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Using millimeters, measure and record the length of your pill bug ____________________.
Graph the length of all the pill bugs in the class.
Gently touch the underside of the pill bug with a dull pencil point. It may be necessary to gently
flip the pill bug over with the pencil to get at its underside. CAUTION: Use care to avoid
injuring the pill bug.
Note its response and time, in seconds, how long the animal remains curled up. Record the time
in the data table as Trial 1.
Repeat steps 6-7 four more times, recording each trial in the data table.
Calculate the average length of time your pill bug remains curled up in a ball.
Post your data in the table below.
Are the times getting shorter, longer, or no change? _______________________
Drawing a Conclusion
Explain how the response to being touched is an adaptation.
Using a Petri dish ands dissecting scope observe creature and. Is it an insect? How can you tell?
Do you have a male or female? How can you tell? (Answer is in Pill bug natural history)
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
Data Table - Collecting Biological Data
Organization and growth and development
Orderly structure?
Pill bug length in mm
Response to environment
Trial
Time in seconds
1
2
3
4
5
Total
Average Time
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Questions:
1. Taxis can be defined as..?
A. Random movements
B. Deliberate movements toward or away from a stimulus
C. Vehicles for hire
2. What is the Independent variable in the Moist/Dry experiment shown in the above
animation?
A.
B.
C.
D.
Moisture
The number of bugs
Bug activity
Time
3. Which of the below are the Pill bugs most closely related to ?
A. Ants
B. Bees
C. Shrimp
D. MCC students
4. What Physiological reason(s) could an animal have for choosing a specific environment?
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Example: light/ dark, Acid/base, warm/cold
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Graph Page
10 9-
Number of Pill Bugs
87654321-
0
1
2
3
4
5
6
7
8
9
10
TIME (minutes)
Question: What conclusions can you draw from your data? Explain any possible reasons
for the observed behavior.
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Pill bug natural history
Classification
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"Pill bugs" or "Sow bugs" Armadillidium Valgare
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Phylum, Arthropoda; Class, Malacostraca; Order, Isopoda
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This group includes shrimp and crabs, they are not
really "bugs".
Appearance (Morphology) Color varies from dark gray to
white with or without pattern
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Three body parts: head, thorax, abdomen
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One prominent pair of antennae (one inconspicuous
pair)
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Simple eyes
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Seven pairs of legs
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Seven separate segments on thorax
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Paired appendages at end of abdomen called uropods
On the underside, females have leaf-like growths at base of some legs. These
brood pouches hold developing eggs and embryos. The first two appendages on
the male abdomen are modified as elongated copulatory organs.
Natural History
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Food
Isopods are omnivores or scavengers feeding on dead or decaying plants
or animals. Some may eat live plants.
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Habitat
Isopods breathe with gills, so they are restricted to areas with high
humidity, under rocks or logs, in leaf litter or in crevices. Some species
are nocturnal.
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Predators
Vertebrates and invertebrates.
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Interesting Behaviors
Some species roll up into a ball when disturbed. Eggs (up to 100) are held
in broad pouch on female. Juveniles look like adults and are soon liberated
from pouch. Molting is in two stages. First the back half molts, then two to
three days later, the front half molts. Coloration of both halves may be
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different at this time. Many species are fast walkers, but can be easily
observed when held in the palm of the hand.
Impact on the Ecosystem
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Positive
In their immediate vicinity, isopods do minimal soil improvement. Isopods are
also a food source for other animals.
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Negative
In greenhouses and southern states, large populations can eat and damage
plants.
Collecting Live Insects
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Where to find
Look under logs, moist leaf litter, flower pots (a day after they have been
watered), outdoor pet dishes, and under paving bricks or stones. Isopods live
where it is moist and usually in a shaded area. To attract them, water soil or leaf
litter in the shade and cover with plastic, piece of plywood or cardboard. Keep
the area moist and check under the covering in a couple days. If you are unable
to find isopods they can be purchased from: Carolina Biological Supply Company.
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How to collect
Before looking for isopods, prepare a container and tools to gather the isopods. If
you are going to set them up in a container with soil in a day, you do not need to
separate them from the soil (see rearing information). To collect them, use a
spoon or shovel and a container. Look under a rock or log and be prepared to
collect the isopods quickly before they scurry away from the light. Gently scoop
up soil with the isopods and place them in the container. Look on the underside
of the log or stone for others. They can be gently picked or brushed off with a
finger into the container. Pill bugs often curl up and can be picked up individually
or scooped up with the spoon. If you are going to keep the isopods a couple days
before placing them in the classroom, use a plastic margarine or cottage cheese
container with small holes poked in the lid and a moistened piece of paper towel
lightly crumple inside. Use an old pie tin to sort the isopods from the soil before
placing them in the container. The paper towel must be kept moist or they will
die. When you are looking under rocks and logs be careful to avoid scorpions,
centipedes and other animals that live there. Return the rock or log to the way it
was when you found it.
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Pill Bug Races
Select a pillbug based on whatever criteria desired.
Place the pillbug in the center of a 60 cm circle drawn on butcher paper.
Record the time it takes to hike 30 cm to the perimeter of the circle. This is the pill bug’s
"qualifying time"
All pillbugs are seeded by qualifying time into a double elimination tournament. Head to head
competition - first bug to the edge wins.
World record time was 9.33 sec for 30 cm, approximately 3 cm/sec !!!
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