the hedgehog's food is in short supply during the winter, so it spends the coldest months hibernating in a specially prepared nest; this is usually at ground level in a hedgerow, a compost heap, under a thick layer of leaves or under logs. Before curling into a tight ball in this hibernaculum, the hedgehog spends the autumn eating as much food as possible to store it as fat which is used up during sleep. If insufficient fat has been stored, the hedgehog may die during a long, hard winter. Hibernation usually lasts from November until March. During this time the body temperature drops to that of its surroundings and breathing almost stops.