"Every day, tiny insect larvae descend into the murky depths of Lake Malawi, one of Africa’s deepest bodies of water." "At night, the larvae return to the surface to feed under the cover of darkness." But unlike other insects, Chaoborus fly larvae don’t use these sacs to help them breathe, instead, they’ve converted them into organs that help them control their buoyancy. Chemical changes in the larvae’s body cause the air sacs to expand “like an accordion” or shrink. When Chaoborus larvae pupate and emerge as flies, he says, they “erupt out of the lake.”