Megabat evolved early in the lineage of chiropterans. Although echolocation was later lost in family Pteropodidae, bats in the genus "Rousettus" are capable of primitive echolocation through clicking their tongues, and some species have been shown to create clicks similar to those of echolocating bats using their wings. Both echolocation and flight are energetically expensive processes. The nature of the flight and echolocation mechanism of bats allows for creation of echolocation pulses with minimal energy use. Energetic coupling of these two processes is thought to have allowed for both energetically expensive processes to evolve in bats. The loss of echolocation may
Animal echolocation Their high intensity calls are necessary to even have moderate detection of surroundings because air has a high absorption of ultrasound and because insects’ size only provide a small target for sound reflection. Additionally, the so-called "whispering bats" have adapted low-amplitude echolocation so that their prey, moths, which are able to hear echolocation calls, are less able to detect and avoid an oncoming bat. Calls can be composed of one frequency or multiple frequencies comprising a harmonic series. In the latter case, the call is usually dominated by a certain harmonic ("dominant" frequencies are those present at higher intensities than