Megabat long, thus smaller than some microbats, for example, the Mauritian tomb bat. The largest attain a wingspan of , and weigh as much as . Most fruit bats have large eyes, allowing them to orient themselves visually in twilight and inside caves and forests. Their sense of smell is excellent. In contrast to the microbats, the fruit bats do not use echolocation (with one exception, the Egyptian fruit bat "Rousettus egyptiacus", which uses high-pitched tongue clicks to navigate in caves). Megabats make up the only family (Pteropodidae) in order Chiroptera that is not capable of laryngeal echolocation. Echolocation and flight
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,