Diversification of gut morphology in caterpillars is associated with defensive behavior.

The relationship between insect gut structure and foraging strategy has been studied for several hundred years; however, we know little about how, or even if, other common insect behaviors are linked to gut morphology. For example, many insects defend themselves by regurgitation, a behavior which is expected to be closely connected to gut structure. Caterpillars belong to an insect taxon, the Lepidoptera, with a particularly well-studied digestive tract and a known predilection for defensive regurgitation.