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
Daubenton's bat also always near water. Daubenton's bat hibernates in the same type of locations from September to late March or April. Daubenton's bat is insectivorous and uses echolocation to find prey and orient itself at night. Bats emit sounds too high in frequency for humans to detect, and interpret the echoes created to build a "sound picture" of their surroundings. Daubenton's bat emits echolocation calls at frequencies between 32 and 85 kHz, though typical calls peak at 45 to 50 kHz; the calls have a duration of 3.3 ms. The bats emerge at twilight to hunt for insects over the water.