 The second proposes that laryngeal echolocation had a single origin in Chiroptera, was subsequently lost in the family Pteropodidae, and later evolved as a system of tongue-clicking in the genus "Rousettus".Individual bat species echolocate within specific frequency ranges that suit their environment and prey types.This has sometimes been used by researchers to identify bats flying in an area simply by recording their calls with ultrasonic recorders known as "bat detectors".