Why do caterpillars smell bad?
An osmeterium is a defensive organ found on Swallowtail butterfly larvae, and is unique to the family Papilionidae. In the pictures to the left, the osmeterium is highlighted in red. It is exerted when the caterpillar is harassed by a predator, and has a pungent odor which drives the predator away. What does a swallowtail…