Pipistrelle bat ear. Coloured scanning electron micrograph (SEM) of the ear of a pipistrelle bat (Pipistrellus pipistrellus). The tragus, the fold that protrudes into the centre of the ear, has been found to be important in echolocation. In echolocation, the bat emits a series of high- pitched sounds, whose echoes are detected by the ears. The echoes are used to build up a three- dimensional map of its surroundings, which is used for navigation and detecting prey.