Hibernation is a period in winter when some animals spend time mostly sleeping or in an inactive state. Animals like bears, squirrels, rodents, and so on hibernate through winter. Hibernation is a survival mechanism in animals to protect them from harsh and cold weather conditions.
Also in the cold weather or winter, most of these animals find it difficult to feed due to food scarcity and loss of green pasture.
When animals hibernate, their heart rate, body temperature, and body metabolism slow down. This can go on for days, weeks or months. Hibernation usually starts around September to October and draws a close around April or May. This duration may differ in some animals.
The process of hibernation is a longterm adaptation mechanism for animal survival.