What stimuli causes an animal to enter hibernation and what stimuli awaken it?

Animals enter hibernation primarily in response to environmental stimuli such as decreasing temperatures and reduced food availability, signaling the onset of winter. The shortening of daylight hours also plays a crucial role in triggering this state of dormancy. To awaken from hibernation, animals respond to rising temperatures, increased daylight, and the availability of food resources in spring, which signal a more favorable environment for activity and foraging.