Egyptian fruit bat their days roosting in trees or caves, often with large groups of other bats, sometimes numbering in the thousands. They emerge from the roost to forage for food in the late evening, and return just before dawn. They hang upside down, with their wings folded closely around their bodies. Egyptian fruit bats, along with other species in the genus "Rousettus", are the only megachiropterid bats to use echolocation, which they accomplish by emitting a series of sharp clicks with their tongues. The clicks are normally slow and constant, but these clicks speed up dramatically when the bats approach an object.
Barbastelle this world, participated in an evolutionary arms race. The foe for the bat order Chiroptera is its prey, the moth order Lepidoptera. To minimize the risk of the bats' echolocation, moths [and in rarest examples, butterflies] have evolved to detect the echolocation calls of hunting bats, and evoke evasive flight manoeuvres, or reply with their own ultrasonic clicks to confuse the bat's echolocation. The Arctiidae subfamily of Noctuid moths uniquely respond to bat echolocation in three prevailing hypotheses: startle, sonar jamming, and acoustic aposematic defence. All these differences depend on specific environmental settings and the type of echolocation call; however,