Staying active: Some animals stay active during the winter, using their body fat and food they stockpiled during the summer months to survive. To conserve body fat, these animals may enter periods of reduced activity or torpor. Squirrels, chipmunks, and bears are examples of animals that stay active during the winter.
Hibernate: Other animals hibernate during the winter. During hibernation, animals enter a deep sleep-like state in which their body temperature, heart rate, and breathing slow down significantly. This allows them to conserve energy and survive on the fat reserves they have built up during the summer and fall months. Common hibernators include bears, woodchucks, and bats.