The only flying mammal in the world is the bat. The anatomy of a bat's wing resembles a human hand's anatomy in several ways. It has long fingers separated by a thin membrane. There are around a thousand species of bats to be found in the world today. The number is comparable to the total number of species of all mammals on earth. They can be said to be 20 per cent of all the species of mammals in the whole world.
A typical characteristic feature of bats is their ability to track their way using echolocation. This is how the brain maps the area around bats by virtue of the returning echoes of ultrasonic sounds emitted by bats.
A large number of bats are known to eat insects. But there are also those that are fond of fruits and nectar. Some even eat birds and small mammals. Lizards and frogs often fall prey to a bat's appetite. There are some species that even eat fish, while those living in South America are known to be fond of blood.
Bats play an important role in the ecological systems of the world by being agents for pollination of flowers. They also disperse seeds around the area they fly. The ability to fly has given them the whole world to inhabit and spread across. Besides some of the oceanic islands, Arctic and Antarctic ends, bats are known to find homes in all parts of the world. Habitats differ as per different species and different seasons.
Bats can be found in tree hollows, cracks and crevices, foliage of trees, and even in man-made structures like houses and buildings.