Final answer:
While chipmunks truly hibernate to survive cold winters, raccoons do not hibernate but can sleep deeply and wake up to forage during winter. Hibernation involves a significant decrease in metabolic rate, helping small animals like chipmunks conserve energy, but is not suitable for all small animals like hummingbirds.
Step-by-step explanation:
Chipmunks are small mammals that enter a state of true hibernation during the winter. However, raccoons do not truly hibernate; they can sleep deeply during extreme cold but can wake up and search for food as temperatures permit. Hibernation is an adaptation used by animals to survive the cold conditions of winter, which involves a significant decrease in metabolic rate, allowing animals such as ground squirrels and some bats to maintain reduced body temperatures for extended periods. In contrast, larger animals like bears go into a state often confused with hibernation, in which they enter deep sleep and their body processes slow down only slightly. Hibernation is a survival mechanism during times when food is scarce, and it is particularly important for small animals that lose heat quickly. However, this state is not suitable for all animals, like hummingbirds, which are too small to maintain the necessary body heat through a prolonged hibernation period.