Nature’s own sonar system, echolocation occurs when an animal emits a sound wave that bounces off an object, returning an echo that provides information about the object’s distance and size.

Over a thousand species echolocate, including most bats, all toothed whales, and small mammals. Many are nocturnal, burrowing, and ocean-dwelling animals that rely on echolocation to find food in an environment with little to no light. Animals have several methods for echolocation, from vibrating their throats to flapping their wings.

Nocturnal oilbirds and some swiftlets, some of which hunt in dark cave environments, “produce short clicks with their syrinx, the vocal organ of birds,” Kate Allen, a postdoctoral fellow in the Department of