EVERYDAY SCIENCE

Detailed explanation-1: -One of the main characteristics that is used to distinguish one class of animals from another is type of skin covering. Mammals have hair or fur, birds have feathers, reptiles have dry scales, amphibians have soft, moist skin, and fish have wet, slimy scales.

Detailed explanation-2: -Hair (and a coat of hairs, called fur or pelage) is uniquely mammalian. No other creature possesses true hair, and at least some hair is found on all mammals at some time during their lives. Hairs grow out of pits in the skin called follicles.

Detailed explanation-3: -The most important function of hair in mammals is that of insulating against cold by conserving body heat. The differing colours and colour patterns in hair coats can also serve purposes of camouflage and of sexual recognition and attraction among the members of a species.

Detailed explanation-4: -Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an insulating blanket that keeps the animal warm.

Detailed explanation-5: -The furs of mammals have varied and complex functions. Other than for thermoregulation, fur is involved in physical protection, sensory input, waterproofing and colouration, the latter being important for crypsis or camouflage. Some of these diverse functions potentially conflict.