Some animals neither migrate nor hibernate when winter comes. Instead, they remain active in their usual environment. To help their survival chances, these animals experience a change or changes in their bodies as the conditions change around them. Most of these changes help them from losing heat and energy.
Remaining active in winter keeps an animal in its home range, the area it uses to find food. However, it may have to expand this range because there is less food available. If snowfall is heavy, animals will have to use up more energy, which can make surviving even more difficult.