As described by the Oaklands Zoo,
Ferrets have a long and slender body covered with brown, black, white, or mixed fur ... Average length is 20 inches including a 5 inch tail. They weigh 1.5 to 4 pounds with males substantially larger than females ... Gestation is 42 days, litters are usually 3 to 7 young, but sometimes more. Females may have two to three litters annually. Young are weaned after 3 to 6 weeks and become independent at 3 months. Sexual maturity may come at 6 months. Average life span is 8 years. —Conservation and Education: Oaklands Zoo
The fur of the ferret is usually brownish, although many variations of colors and patterns exist. Some common colors that may be seen in ferrets include: albino (white fur and pink eyes), sable, chocolate, silver and cinnamon with patterns such as mitts (white feet), panda (white head), badger (white blaze) and Siamese (dark legs and tail).  Males are generally larger than females.
Ferrets are crepuscular, which means they 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, ferrets will live happily in social groups. They are territorial, like to burrow and prefer to sleep in an enclosed area. Like many other carnivores, ferrets have scent glands near their anus, the secretions from which are used in scent marking. It has been reported that ferrets can recognize individuals from these anal gland secretions, as well as the sex of unfamiliar individuals. Ferrets may also use urine marking for sex and individual recognition. As with skunks, ferrets can release their anal gland secretions when startled or scared, but the smell is much less potent and dissipates rapidly. Most pet ferrets in the US are sold de-scented (anal glands removed). In many other parts of the world, including the UK and other European countries, de-scenting is considered an unnecessary mutilation. When excited, they may perform a routine commonly referred to as the weasel war dance, a frenzied series of sideways hops and bumping into things. This is often accompanied by a soft clucking noise, commonly referred to as dooking. Diet
Ferrets are obligate carnivores. The natural diet of their wild ancestors consisted of whole small prey, i.e., meat, organs, bones, skin, feathers, and fur.
Ferrets have four types of teeth (the number includes maxillary (upper) and mandibular (lower) teeth) Twelve...