When You Yell, Why Do Caterpillars Dance?

Caterpillars dance when you yell because they can detect vibrations made by loud noises, which indicate a potential threat. This defense mechanism could potentially save their lives. The sound frequencies to which caterpillars are most sensitive match the flight sound of a fly parasite that lays eggs on their heads. The caterpillars hope to scare off whatever it is that may want to do them harm. A viral video shows what happens when you yell at caterpillars, and their reaction is very odd.

There are a few types of caterpillars, namely Monarch and Queen caterpillars, that “dance” in response to loud noises or music. After each shed, the caterpillars find themselves immediately vulnerable. Their arsenal of defensive setae, or hairs, are wet and matted and relatively useless against tentacled caterpillars. However, this weird behavior is an anti-predator tactic. The caterpillar probably deploys the structures to avoid being attacked by predators.

Loud noises are associated with predators, especially parasitic insects, and they try to scare you off. Some caterpillar species wiggle their heads when they think they are in imminent danger of being attacked by a predator. It’s like when you start yellin, they start dancin. Caterpillars writhe their bodies and shake their heads when they hear loud sounds because they are warding off potential attacks from parasites.