How do the hair of certain animals help in keeping their bodies warm?

Animals that live in cold climates often have thick, fur coats that help to keep them warm. This fur acts as an insulator, trapping pockets of air close to the body and preventing heat from escaping. This can make a significant difference in a cold environment, as the fur is often much thicker than our own clothes. Some animals have multiple layers of fur, with the outer layer being longer and coarser to help shed water, and the inner layer being shorter and softer to provide insulation. The thickness of the fur and the number of layers vary depending on how cold the climate is.

Additionally, some animals are able to change the thickness of their fur depending on the time of year, with more fur growth in winter and shedding in spring and summer. This ensures that they are kept warm in the coldest months but don't overheat in the warmer months.