Flea

A flea can leap many times its own body length, a trick powered by a springy protein called resilin that lets it jump onto passing animals. These tiny, wingless insects feed on blood and are a familiar headache for dog and cat owners. Much of a flea population lives not on the pet but in carpets and bedding as eggs, larvae and pupae. Our guide to the flea life cycle explains each stage and why fleas are so persistent.