What are the animals that hibernate?

The animals that hibernate are frogs, toads, snakes, earthworms, bears, crocodiles, hedgehogs, turtles, squirrels, bats, ants, wasps, lizards, and snails.

Amphibians mostly need to hibernate, similar to snakes, lizards, and turtles, and will find their own nests to crawl into for hibernation once winter arrives. But some animals, like bears, don't really hibernate. They do sleep more in the winter than they do in the summer, but it's not a slumber like hibernation.

On warm, sunny winter days, bears, squirrels and chipmunks wake up and go outside. The sleep of a true hibernating animal borders on death, with all vital activity virtually ceasing. Body temperatures drop to just slightly warmer than the air temperature in the burrow. Because of this, the animal consumes the food stored in its body very slowly.

Expanded:

Hibernation is a process that occurs in different ways. p>The length of hibernation varies with the animal. European hedgehogs 3 to 4 months. Hibernating rats can sleep for 6 to 7 months. But it cannot simply be assumed that hibernation is a months-long uninterrupted process; rather, more commonly hibernation is intermittent, with long periods of rest and low metabolism interspersed with brief periods of awakening.

But animals can't return to the waking state very often, because each waking is energy intensive, and waking too often can lead to premature depletion of fat stores, so that there's no "fat" available for the real awakening in the spring of the following year.

An increase in ambient temperature and a buildup of metabolites may signal awakening. Hibernating animals slowly raise their body temperatures as they awaken. Hormones cause the breakdown of brown adipose tissue, which provides energy for the initial rise in body temperature.