Sometimes the best way to deal with winter is to just say "forget it" and sleep through it. That's what many of our animal friends do when the weather gets too cold and food becomes scarce, but which animals actually hibernate? Some animals go into true hibernation: their heart rates and metabolisms slow down, and they pretty much don't wake up until spring. Other animals go into something called "torpor," or a light hibernation, and might sleep for days or weeks at a time, but they get up occasionally if disturbed or if they want a midnight snack. One animal even freezes, develops ice crystals in its blood and appears dead, but still thaws out in the spring like nothing happened.Scroll through this list of the animal world's champion sleepers and find out which critters have woken up from a long winter's nap. The next time you feel guilty about sleeping in, rest easy knowing that you have nothing on these guys.
Bears are the first animals people think of when you say "hibernation," but they are actually light hibernators. They go into something called torpor, which means they can be easily awoken. They do this during the cold months for six months and rarely urinate or defecate during that time.
Bats go into such a deep hibernation that they appear to be dead. Their heartbeat drops from 400 to 25 beats per minute and they might not take a breath for a whole hour.
The wood frog hibernates inside logs or burrows under rocks or piles of leaves. These hard-core hibernators actually stop breathing, their hearts stop, and ice crystals form in their blood. Then, when it gets warm, they thaw out and hop back to life.