Caterpillars Use Anal Drumming to Attract New Friends

How is a minuscule caterpillar able to talk other caterpillars into living communally? With its butt, of course. When masked birch caterpillars hatch, they are less than 1 mm long ­– about the size of a grain of pepper. Yet somehow, they find other young caterpillars and form social groups in silk shelters on birch leaves.Now, scientists have figured out how they locate one another. Read about the research in my latest for National Geographic's Weird & Wild news: Caterpillars Drum Their Anuses to Find New Friends.