Definition
Hibernation is a type of deep sleep that allows some animals to survive a cold winter. During winter, there is often less food available for animals. This is one of the reasons many animals choose to hibernate. Before winter starts, hibernating animals build up their fat stores by eating more food than usual. They then find a warm spot where they are not likely to be disturbed for a long time. During hibernation, hibernating animals' heart rate decreases, their breathing rate decreases and their temperature decreases. All of this leads to lower metabolism. (the amount of energy needed to keep them alive)