Brown bears, including grizzly bears, hibernate during the winter months. They enter a state of torpor, slowing their metabolism and conserving energy by living off stored fat reserves until spring.
Eastern chipmunks hibernate in their underground burrows during the winter, entering a deep sleep-like state and living off cached food supplies.
Hedgehogs hibernate in the winter to conserve energy. Their body temperature drops, and they become less active, relying on stored fat to survive until warmer weather arrives.