Do you know how caterpillars fend off hungry birds and other predators? Surprisingly and interestingly – by clicking at them! The insects click to warn that they will be unsavory to eat, especially after regurgitating a foul brown fluid, scientists explain.
Green-colored common silkmoth caterpillars (Antheraea polyphemus) were studied to understand the catterpillars’ clicking and barfing. The study was headed up by neuroethologist Jayne Yack at Carleton University in Ottawa.
Though the caterpillars mostly rely on camouflage for protecting themselves, they use clicks and regurgitation as last resorts. These upchucked fluid, along with the advance clicking warning definitely are effective deterrents, according to Yack.
Yack recalled,
My cat got into a caterpillar bin at my house once. When I got home, there was a caterpillar that was still alive outside the bin with a long string of regurgitant trailing from it, and my cat was gagging. For years after that, whenever my cat saw a caterpillar, she started gagging. There’s a strong learning component there, and the sounds can help with that.
The details of these findings are published on March 2 in the Journal of Experimental Biology.