As for bears, while they are certainly less active during the winter, they do not truly hibernate. Instead, they take very long naps known as “winter sleep.” In winter conditions they find protected areas like a cave or hollow log and conserve energy by taking extended naps. This is why it is always dangerous to disturb a wintering bear, because it is merely napping, not hibernating. In zoos, because temperatures in cages and enclosures remain warm throughout the year and the bears have access to a food supply continually replenished by keepers, bears remain active year-round.