A bat is a mammal in the order Chiroptera. Their most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals in the world naturally capable of flight. (Other mammals, such as flying squirrels, lemurs, and flying opossums, can glide for limited distances). There are estimated to be about 1,100 species of bats worldwide, accounting for about 20 percent of all mammal species (Trudge 2000).
FeedingMost microbats depend on a diet of insects. These are most often caught in the air while flying, although some bats capture insects on the ground or from plants. Some of the larger microbats eat larger animals such as fish, frogs, mice, small birds, or even other bats. In the New World where megabats are absent, some microbats have taken to diets of fruit or nectar. The vampire bat of South America (Desmodus rotundus) drinks the blood of living animals.
ReproductionPups are usually left in the roost when they are not nursing. However, a newborn bat can cling to the fur of the mother and be transported, although they soon grow too large for this. It would be difficult for an adult bat to carry more than one young, but normally only one young is born.
Bats often form nursery roosts, with many females giving birth in the same area, be it a cave, a tree hole, or a cavity in a building. Mother bats are able to find their young in huge colonies of millions of other pups. Pups have even been seen to feed on other mothers' milk if their mother is dry. Only the mother cares for the young, and there is no continuous partnership with male bats.
The ability to fly is congenital, but at birth the wings are too small to fly. Young microbats become independent at the age of six to eight weeks, megabats not until they are four months old. At the age of two years, most bats are sexually mature. A single bat can live over 20 years, but the bat population growth is limited by the slow birth rate.