Bears are big and incredibly strong. Most animals won't go near them, but there's one thing they're most afraid of: winter.
Bears are animals that, like us, always have a constant body temperature (body heat). They're called ectotherms because they need a lot of energy to stay warm. They need to eat a lot more food in the winter, when it's colder, and food is harder to come by.
It's so cold that many living things die or go into hiding. Plants wither, and insects and small animals hibernate to escape the cold. Bears have no choice but to hibernate, too. Luckily, bears have a lot of food stored up for the winter, so they can hibernate in peace knowing that they're fattened up and can use their energy reserves to get them through until spring.
A hibernating bear may look like it's sleeping very deeply, but you should never disturb it. If you do, he might wake up right away. Bears aren't really sleeping, they're just dozing off. They're able to give birth and raise their cubs while hibernating, and their muscles don't shrink even though they're not moving. Normally, muscles shrink when they're not used, as the body reduces muscle mass in areas that aren't being used to conserve energy.
Bears have special muscle cells that allow them to maintain their muscles even when they're still, which makes them very enviable for people who like to exercise.
The question here is, what do bears do when they need to pee in their sleep? We wake up in the middle of the night when we need to pee.
Interestingly, bears don't have to pee or poop very often because their bodies recycle their waste. Don't you envy a bear that doesn't have to go to the bathroom and builds muscle while sleeping?
Do bears in zoos hibernate? Bears in zoos have access to food all the time, so they don't need to hibernate to conserve energy.
