Egyptian fruit bats, Rousettus aegyptiacus, roost in caves and even pyramids; they are depicted on tomb artwork thousands of years old. Some of these bats are able to penetrate into the darker depths of their caves as they are able to echolocate by tongue-clicking and listening for the echo, thus producing a cruder version of the microbats' echolocation system. This is unusual behaviour, as most megabats roost out in the open, hanging communally from the upper branches of trees within a small area.

The megabats, or Old World fruit bats, can be distinguished from microbats by a number of distinctive features:

• long snout
• wrap-around wings when hanging from perch
• big eyes
• second claw in finger, as well as on thumb
• lack of sophisticated echolocation system (in some species, primitive version only)
• found throughout the tropical and subtropical regions from Africa and Asia to Australia, particularly diverse in South-East Asia, New Guinea, Australia and some Pacific islands; absent from the Americas

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