Including their tail, the average length of a ferret is about 50 cm (20 in); they weigh between 0.7 and 2.0 kg (1.5 and 4.4 lb); and their fur can be black, brown, white, or a mixture of those colours.

Ferrets may have been domesticated since ancient times, but there is widespread disagreement because of the sparseness of written accounts and the inconsistency of those which survive.

In North America, the ferret has become an increasingly prominent choice of household pet, with over five million in the United States alone.

In New Zealand and some other countries, restrictions apply due to the damage done to native fauna by feral colonies of polecat–ferret hybrids.

[3] The Greek word ἴκτις íktis, Latinized as ictis occurs in a play written by Aristophanes, The Acharnians, in 425 BC.

Other purported collective nouns, including "besyness", "fesynes", "fesnyng" and "feamyng", appear in some dictionaries, but are almost certainly ghost words.

[14] As with skunks, ferrets can release their anal gland secretions when startled or scared, but the smell is much less potent and dissipates rapidly.

If excited, they may perform a behavior called the "weasel war dance", characterized by frenzied sideways hops, leaps and bumping into nearby objects.

[18] The natural diet of their wild ancestors consisted of whole small prey, including meat, organs, bones, skin, feathers and fur.

Treatment options include surgery to excise the affected glands, melatonin or deslorelin implants, and hormone therapy.

The causes of adrenal disease speculated to include unnatural light cycles, diets based around processed ferret foods, and prepubescent neutering.

[28][29][30] A high proportion of ferrets with white markings which form coat patterns known as a blaze, badger, or panda coat, such as a stripe extending from their face down the back of their head to their shoulder blades, or a fully white head, have a congenital deafness (partial or total) which is similar to Waardenburg syndrome in humans.

According to phylogenetic studies, the ferret was domesticated from the European polecat (Mustela putorius), and likely descends from a North African lineage of the species.

[38][39] Genghis Khan, ruler of the Mongol Empire, is recorded as using ferrets in a gigantic hunt in 1221 that aimed to purge an entire region of wild animals.

[3] Colonies of feral ferrets have established themselves in areas where there is no competition from similarly sized predators, such as in the Shetland Islands and in remote regions in New Zealand.

On the voyage, the ferrets were mated with the European polecat, creating a number of hybrids that were capable of surviving in the wild.

[41] Concern was raised that these animals would eventually prey on indigenous wildlife once rabbit populations dropped, and this is exactly what happened to New Zealand's bird species which previously had had no mammalian predators.

With their long, lean build and inquisitive nature, ferrets are very well equipped for getting down holes and chasing rodents, rabbits and moles out of their burrows.

[3][42][43] In England, in 1390, a law was enacted restricting the use of ferrets for hunting to the relatively wealthy: it is ordained that no manner of layman which hath not lands to the value of forty shillings a year shall from henceforth keep any greyhound or other dog to hunt, nor shall he use ferrets, nets, heys, harepipes nor cords, nor other engines for to take or destroy deer, hares, nor conies, nor other gentlemen's game, under pain of twelve months' imprisonment.

Ferreting was chosen because in populated areas it is considered to be safer and less ecologically damaging than shooting the rabbits.

[70] A very small experimental study of ferrets found that a nasal spray effectively blocked the transmission of the SARS-CoV-2 coronavirus that causes COVID-19.

[72][73] Most ferrets are either albinos, with white fur and pink eyes, or display the typical dark masked sable coloration of their wild polecat ancestors.

This causes, among other things, a cranial deformation in the womb which broadens the skull, white face markings, and also partial or total deafness.

Illustrations show how multicolored ferrets that were fitted with muzzles were used to chase rabbits out of their warrens and into waiting nets.