Evolving a Defense, Mimics Save Themselves

A Canadian tiger swallowtail caterpillar has made itself look like a snake. Credit Thomas Hossie

Carl Zimmer

The Canadian tiger swallowtail caterpillar is a plump green creature that spends all its time munching leaves. It ought to be an easy meal for a bird, yet many birds pass it by.

The caterpillar is protected by a remarkable defense, researchers have found: It tricks birds into thinking it’s a snake. Read more.