Hibernation is how many creatures survive winter. Hibernation is a state of minimal activity and metabolic depression, enabling them to survive without having to forage for food, and can involve extended periods of deep unconsciousness, in which the dormant animal is vulnerable to predators and the climate.

Many animals hibernate. The type of hibernation, or hibernation strategy is determined by three main factors:

• Food supply – insectivores or small herbivores will not be able to find food if there is snow and have to survive the winter without food. Larger herbivores can clear snow to find food.
• Body size -large animals can better insulate themselves than small animals.
• Gestation period -young animals must be born in spring so they can become strong to survive the winter, for other species the mating season falls into winter, making hibernation unviable. These species remain active throughout the season.

During hibernation, animals slow their heart and breathing rates and lower their body temperature and metabolism. Hibernating animals do not typically sleep for the whole of the hibernation period and wake occasionally to eat if they have gathered food and go to the toilet. The hibernation period varies between species but is determined by temperature, hedgehogs may not hibernate until late December or even the new year if it is a mild winter, whereas bats typically hibernate from November to April.

Sources: Woodland Trust, Reconnect With Nature, National Geographic, Natural Sciences, Discover Wildlife