Members of Chiroptera order are unique among mammals as they are the only group to have evolved true powered flight. Bat wings are modified forelimbs, much as are bird wings, except in the case of bats the flight surface is covered with skin and supported by four fingers, while in birds the flight surface is provided mostly by feathers and is supported by the wrist and two digits. The flight membrane usually extends down the sides of the body and attaches to the hind legs. Bats also often have a membrane called a uropatagium that runs between their hind legs and includes their tail.
Bats have very small, almost imperceptible eyes surrounded with a short velvet hair, so they probably have pooor eyesight and orientate themselves with the help of ears. The ears are well developed and highly important in bats' aerial feeding activities.
During the flight bats are constantly emiting ultrasounds (20 to 200 thousand vibrations a second), which are reflected from the surroundings and help bats to guide in flight. Bats sleep hanging head first in any closed places like caves, rock crevices and trees. Some bats are solitary, while others are found in colonies that may include over a hundred individuals of one or different species.
Bats eat small insects - gnats, midges, butterflies and beetles. Many of them are harmful for agriculture and forestry. That’s why annihilating them bats are of great use. Like other insect-eates, bats are very gluttonous. However, in bad weather they stay at their day roost and can survive long starvation.
Bats are hunting for food in various places - on meadows, glades and forest edges, sometimes at the streets of small towns and villages. Bats need water. They drink on the wing making a low-level flight above lakes and rivers. The majority of bats spends the winter in the places of summer roost, most of them hibernate for 5-7 months. At this time all their vital proccesses are slowing down. The number of respiratory movements declines to 5 or 6, the temperature of their body falls to 0 C.
