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.
Bulldog bat are long and narrow and their ears are large and funnel shaped. Unusual among bats, they have cheek-pouches for storing food. They also have full lips divided by a fold of skin giving a 'hare lip' look which together with the cheek pouches gives them their bulldog-like appearance. The species of lesser bulldog bats are insectivorous and whilst the greater bulldog bats also eat insects their chief food is fish. They use their echolocation to pinpoint the ripples they make on the surfaces of water. The greater bulldog bat trawls the water with its long, curved talons approximately 2–3 cm