Who doesn't know that bats landing... oh, some wrong word... well generally, when they come in the land, they head over heels cling to something and so hang. Why him not to land on paws as all normal beings?
And that is why...
The scientific group of Brown University for many years studies the principles of flight of wing-handed animals — bats and the krylanovykh. These animals — masters of aerodynamics and maneuverability — first of all, because of a unique structure of their wings. Existence of a large number of joints and a thin flexible film allows to use a wing in flight by a set of ways, including to carry out a turn by 180 degrees.
Helps to keep energy during flight folding of wings at each wave up. Though forces are spent for it, the overall balance is positive. For this reason animals don't fly to a rain: to put wet wings it appears too energy-intensive. Also the secret of an unusual vertical landing of bats is opened. Before performance of action of a bird only dump speed, but bats needed to develop own ways. Having easy and brittle bones, they possess disproportionately massive wings. Owing to such structure of a body of an extremity when landing have to experience big shock strain that leads to damages. Seeking to minimize these consequences, bats "have evolutionarily invented" several acrobatic maneuvers, finishing flight in two or four "contacts".
Tactics of "four contacts" has been recorded at a number of the wing-handed animals eating vegetable food, in particular — Malayan the korotkonosykh of fruit-bats (Cynopterus brachyotis). During the experiments scientists have noted that to a ceiling those fly up with the spread wings. At the time of contact with the surface of an extremity are extended, and animals grab any available ledge thumbs of forward extremities along with fingers of back extremities. After that they make somersaults through the head back and, at last, hang headfirst. At such landing the fruit-bat tests quadruple overloads and can hit the head therefore in the nature the wing-handed animals using tactics of "four contacts" most often land on trees: their surface is softer in comparison with stone caves
In "two contacts" land the zemleroykoobrazny dlinnoyazyky vampire (Glossophaga soricina),-point листонос (Carollia perspicillata) and many other species of wing-handed animals. They have learned to count precisely distance to a surface, flying up to it perpendicularly and at the latest moment sharply deviating to the right or to the left. They grab a ledge only fingers of back extremities thanks to what the landing passes more smoothly, and overloads at blow make only one third of body weight. It allows them to live in caves.
Such situation has pluses — for example, thus bats are much better protected from predators.
And what will be if the mouse falls to the ground?
We remember that evolution at first has made femurs of mice too thin what they could hold the body in a sitting position. Then they have completely lost an opportunity to fly up from a plain surface as they didn't have enough no forces properly to make a start from the earth, speed for running start. Nevertheless, they have learned to fly up from situation headfirst, however, as you understand, for this purpose the free space below is necessary. Besides, these amusing small animals can just fall, straightening the wings already in flight.
And if the mouse suddenly appears on the earth, then she will try to get in every way on some tree or a ledge, in passing clinging to any support the tenacious claws on wings.
How they manage not to fall, they all night long hang on paws headfirst? And the matter is that the bat doesn't spend energy for keeping when hangs headfirst. At bats the special device of muscles. For example, when the monkey hangs on a branch, strains muscles of paws to keep, and at bats everything is arranged exactly the opposite. When she hangs headfirst, her muscles are relaxed, fingers are compressed, the body hangs on bones and sinews, muscles are completely relaxed. Claws densely clasp a support and body weight doesn't allow them to be unclenched.