Many animals hibernate during parts of the year , entering a state that is similar to a very deep sleep . But hibernation is more then simply a deep sleep . The animal’s body temperature drops well below its normal range, the animal does not wake up for a long period of time , and its metabolism slows to the point that the animal does not need to eat or relieve itself during that period.
In order to prepare for hibernation , the animal must build up its body weight and increase its body fat . This is important , since the animal will be living off its owe body fat during the months of hibernation . of course , once the prilod of hibernation is over , the animal “ wake up ” to find itself slim and trim once againl.