Lab activities using live specimens always seem to catch students' attention faster than those using inanimate materials. For example, many teachers are familiar with the activities using goldfish to study the effect of temperature on respiration rate. Insects are particularly useful because they are cheap, easy to find, and have a certain "yuck" factor included. This article presents a lab activity that allows students to investigate animal behavior and design their own experiments using an ideal study subject for the classroom: eastern tent caterpillar ("Malacosoma americanum"). (Contains 6 figures.)