I have very long teeth. I want to keep them all. My house has fiberglass in it. Blankets insulate people when they are sleeping. Carpet is so fluffy it insulates.
Snow is another insulator.
Some people put snow against their house to keep it warmer. Dirt is a good insulator for creatures' homes because it will keep them warm. Fiberglass helps keep it warm in your house. Straw helps keep you warm if you go deep in the haystack. Cotton balls have trapped air space so they would be a good insulator.