Hibernation

It is quite well known that many animals hibernate during periods of cold weather. Reptiles and amphibians in particular are known for this sleep behavior. A few mammals, fish and insects also follow such behavior.

Hibernation is not actually a state of sleep; it is a state of physical dormancy, the degree of which varies from animal to animal. During this period, the animal’s body temperature drops, its respiration and heartbeat slow, and its metabolic rate drops considerably. It is believed that hibernation is an instinctive behavior that anticipates certain natural conditions that occur during the animal’s normal time of hibernation. Specifically, the lack of food during winter months is thought to be the reason for hibernation, rather than the actual colder temperatures. On the other hand, some animals go into hibernation during the hot, dry seasons of tropical climates. Probably because at this time both food and water are scarce. However, this behavior is not called hibernation. Rather, it is referred to as estivation.