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
Bat species identification (or "Pips") give good examples of what can be discovered with a bat detector and make a good start to learning how to identify bats. Bat detectors pick up various signals in the ultrasound range, not all of which are made by bats. To distinguish bat and bat species it is important to recognise non-bat species. Captured bats can be exactly identified in the hand but in many countries a licence is required before bats can be captured. There are four basic types of bat echolocation call. The term "frequency modulation" (FM) refer to the "chirp" type of bat call.