Ferrets White: The ferret (Mustela putorius furo) is the domesticated form of the European polecat, a mammal belonging to the same genus as the weasel, Mustela, in the family Mustelidae. Their fur is typically brown, black, white, or mixed. They have an average length of 51 cm (20 in), including a 13 cm (5.1 in) tail, weigh about 1.5–4 pounds (0.7–2 kg), and have a natural lifespan of 7 to 10 years.
White ferrets turn yellow because of the naturally occurring oils on their body. These oils help ferrets regulate their body temperature and also communicate with other ferrets. Sable ferrets have this oil as well but it is not as visible due to their darker coat. The white ferret’s sebaceous glands (microscopic glands that secrete oil to lubricate or waterproof the hair of a mammal) cause a release of oil that is yellow in color.