After the pillbugs have been in the choice chamber for 10 minutes, you might observe one of these situations:

Pillbugs are crustaceans, and they respire through gills. Because of this characteristic, which situation would you predict to occur — A, B, or C?

Based on the previous information, and knowledge that pillbugs are found in moist environments, most people would predict situation B. This is often what occurs, but not always! Situations A and C are also common.

This brings us to an important consideration: The pillbug exercise is not a controlled experiment. Could there be more light at one end of the choice chamber? More activity and vibration? A chemical residue on one side? Any of these conditions and more could possibly influence the organism's behavior. Without a control, it is very risky to state a conclusion.

In the second part of the Animal Behavior lab, you design a controlled experiment.