With the onset of winter, days shorten and temperatures drop.
Animals meet winter’s challenges in different ways. Some mammalian species like chipmunks, bats, and bears experience different types of dormancy, lowering their body temperatures, slowing their heart rates and metabolisms, and going without food for periods ranging from several days to several months.
Reptiles have their own version of dormancy, called brumation, often going for months without food and oxygen, but drinking water throughout the period.
Foxes and deer grow heavy winter coats.