The bats, destroying insect pests with nightly summer, in the middle lane completely disappear in the fall.
To survive the cold season, without having a forage base, these winged animals adapt effectively to habitat conditions. It is known that the bat in winter hibernates.
Winter sleep and winter flight
With the onset of cold weather part bats migrates to the southern regions, flying hundreds of kilometers in search of outgoing heat. 
However, many species - nightgowns, ushans, evening girls - stay for the winter in the same places where they hunted in the summer. These bats are sleeping in the winter.
They are looking for a suitable shelter, are hammered into cracks or are reliably attached by paws to walls or ceilings, hanging upside down, and hibernate for a total duration of 6-8 months.
Some animals can absolutely still sleep for up to 5.5 months in a row, without leaving a state of deep anabiosis.
A long period of minimal vital activity increases the life expectancy of bats to 15–20 years, and some specimens live to a record 30 years.
If during wintering the temperature in the shelter decreases significantly, or the sleeping animals are disturbed, they can go out of hibernation and migrate to a safer haven.
ATTENTION: Forced awakenings with flights take a lot of energy and animals that again fall into anabiosis may not survive until spring.
Optimum wintering sites
So where are the bats wintering, are the bats sleeping in the winter and sleeping?
In order to successfully winter, bats need reliable no drafts shelter with temperature from 7-8 degrees to zero (but not below) and humidity from 80 to 100%.
In the middle zone conditions, such a winter environment is created in the dungeons, caves and basements, mines and galleries, in log cabins of deep wells, in attics, in hollows of old trees.
Often, animals move to wintering shelters in colonies numbering up to several hundred individuals. Large communities of bats winter in empty abandoned pillboxes of the war, in the forts of the Brest Fortress.
It is not easy to find a suitable place, therefore winged mammals perfectly remember not only the attic, cave or basement, but also that particular area where they are located in it. From year to year, the bats return exactly to the same place where they have already managed to safely winter.
A photo
Look at the photo: how bats winter
Bat in town
In connection with the invasion of humans into the natural habitat of bats, animals master the previously unusual area of urban buildings and structures.
Where do bats winter in the city? They take on winter apartments in the cracks and seams of high-rise buildings, climb into attics, huddle under the lining of the balconies, between the window frames and in the slots of air conditioners, are located in warmed basements and vegetable stores.
Close human presence is a great danger for bats. If they are disturbed in the winter, they freeze, trying to find a new shelter, or become easy prey for cats and dogs.
The bat found in the city in the winter, above all, provide water to drink. Then you can send the animal to hibernate again in a box or pouch, finding a suitable place in the refrigerator.
Some lovers leave the animal awake at home, providing it needs plenty of feeding live insects like mealworms.
In the spring, however, temporary captives must be set free.
Settlement of bats for wintering in a certain building can be considered a peculiar sign of "environmental quality", since these animals are sensitive to the natural habitat and don't settle in places, polluted harmful chemicals.
However, the neighborhood with large colonies of wintering animals in the city delivers certain inconveniences.
In such cases, in the fall, when bats wander to undesirable places in winter urban shelters, special ultrasonic repeller.
Tireless nocturnal hunters of insects - winged mammals - in most regions of the middle belt are rare and endangered species. They are sensitive to environmental pollution, hardly maintain their numbers and, at the same time, have the unique ability to survive the winter cold.
Bats should not be disturbed at wintering grounds, as hibernation takes them a lot of energy and the animals do not live to the new spring hunting season.
