The body is compact allowing the bat to wriggle free of a predator's grip. Whilst all bats possess wings formed from a double membrane stretched between the elongated fingers, the evening bats also have a membrane stretched between their ankles and nearly enclosing the tail, known as the interfemoral membrane.
This membrane is unusually furry in the brown tube-nosed bat. Whilst this species finds its insect prey using echolocation, its ears are small for its size. As the brown tube-nosed bat holds its mouth open much of the time in order to echolocate, it is easy to see its large, sharp teeth, used to crush hard-bodied insects.