Echolocation is the process by which bats emit high-frequency sound pulses through their mouth or nose and listen to the echoes that bounce back to determine the location of objects in their environment. Bats use echolocation to navigate and find food in the dark, and they can detect objects as thin as a human hair in complete darkness. Bats emit ultrasonic calls ranging in frequency from 11 kilohertz up to 212 kilohertz, and most insectivorous bats echolocate in the twenty to sixty kilohertz range. Bats can use echolocation to communicate with other bats.
When the sound waves hit an object, they produce echoes that bounce off the object and return to the bats ears. Bats listen to the echoes to figure out where the object is, how big it is, and its shape. Using echolocation, bats can determine the size and texture of an object, how far away it is, and what direction it is moving in. Bats can also use echolocation to produce a "feeding buzz" when they detect an insect they want to eat. They produce a rapid series of calls to pinpoint the exact location of their prey, then swoop in to catch it.
Bats emit ultrasonic calls that are beyond the range of human hearing, but some bat sounds, such as the squeaks and squawks that bats make in their roosts or between females and their pups, can be detected by human ears. Other animals that use echolocation include whales, dolphins, porpoises, oilbirds, and several species of shrews, tenrecs, and swiftlets.
