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.

Pill bug natural history

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.

Pill Bug Sketch

Example Data: General Observations

• 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.

1. 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 animation). 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. When you are done return the pill bugs to their container.

Pill Bug Ethology Simulated Experiment (click the arrow to begin!) Print the Data Sheet (4 pts.) that results to turn in to your instructor and to graph your results on the Graph Page below.

Graph the number of pill bugs in the wet and dry chambers: Click here to obtain a Graph Page. Follow the graphing instructions below:

Graphing Instructions (8 pts.): 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.

Click the red button to "walk thru" a demonstration of this week's experiment.

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.

Turn in to your instructor: Print the Record Sheet from the Simulated Experiment above, the Graph Page on which you have drawn your graph, answer the Questions below, then press submit and print your Response Page.