bears ,some squirrels, weasels
Hibernation
Some animals sleep through the winter -- those animals are called hibernators. The long sleep through the winter is called hibernation.
Winter sleep is called hibernation. Hibernation is when animals (such as bears) sleep for multiple months in order to conserve energy during the winter.
some animals have to sleep the whole winter. That's why they eat so much in the winter so they can sleep through he whole winter and wake up in spring.
They Mostly Sleep
bears sleep through winter to conserve food, especially during winter when food is short, tapping energy reserves, body fat, at a slow rate. you can find out more at here: http://en.wikipedia.org/wiki/Hibernation
yes
A long deep sleep done by animals during winter
Their bodies will live off their body fat as they ‘sleep’ through winter. The animal will use up the body fat it stores and not lose any muscle. This causes the animal to come out of hibernation thinner but still as strong as it was in the fall.
some animals that can survive the winter and not the summer go for long summer sleep.
hibernation
Because they need to store up fat to be able to sleep all through winter. So they don't starve, as they're not going to eat for all of Winter.