A polar bear's skin is black underneath its fur, which looks pale in sunlight.

The longer version

Under the pale coat, the skin of a polar bear is black, and that dark surface absorbs solar radiation rather than reflecting it. The arrangement works like a one-way system: sunlight passes down through the fur, reaches the skin, and the heat is held close to the body.

The hairs themselves are not white pigment but transparent and hollow, scattering and reflecting visible light so the animal appears pale against snow and ice. Hollow fibres also trap air, adding insulation, and the oily surface sheds water after a swim so the coat does not become a sodden conductor of cold. Beneath the skin lies a thick layer of fat that completes the insulation.

Where this entry sits

This collection gathers small surprises about mammals, reptiles, amphibians, birds, fish, insects, and the pets living alongside people. Expect odd details about senses, anatomy, and everyday behaviour that many people never notice in the animals around them. The full list sits on the Animals page, where every entry is listed in order.