Reindeer are among the most famous animals ... In the winter months, they boast a thick grey or white fur that helps to keep them warm. In the summer, some of the fur sheds off and becomes darker.

A survival expert, the polar bear has a thick layer of fat underneath its skin to protect it from the cold. Like the reindeer, it has two layers of fur: an outer layer that is thicker to protect ...

They are called reindeer in northern Europe and Asia ... find plants and lichen on the tundra below the snow. Their fur is very thick, and their long hollow hairs help trap air close to the ...