The ferret is the domesticated form of the European polecat, a mammal belonging to the same genus as the weasel, Mustela of the family Mustelidae. They typically have brown, black, white, or mixed fur. Ferrets spend 14–18 hours a day asleep and are most active around the hours of dawn and dusk. Unlike their polecat ancestors, which are solitary animals, most ferrets will live happily in social groups. The average life span is 7 to 10 years.