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
Crawford's gray shrew Instead, it builds small nests in pack rat houses or under dead agaves. This species also conserves water by being nocturnal, unlike other shrews, which hunt day and night to avoid starvation. Crawford's gray shrew has poor vision, so it uses its highly sensitive ears and long nose to hunt down its prey. It will also use an echolocation, similar to bats, with high-pitched squeaks to locate prey. It will also store food during the night so it will not have to go out during the day. To keep from losing any water from its victims, it will bite off