The origin of ferrets as a domestic animal is unclear. Ferrets belong to the weasel family (Mustelidae) and are related to mink, skunks, weasels, otters and badgers. Ferrets are the only domestic subspecies in this family and they should not be confused with the Blackfooted Ferret, an endangered species which is only distantly related. Ferrets are dry temperate climate creatures - they have a summer and winter coat, tolerate cold well but suffer when temperatures exceed 20C, and have a breeding cycle attuned to the length of day. Their closest wild relatives, those with which they can interbreed, are the European polecat and the Steppe polecat, found in Eastern European forests southwards into the Balkans and the Caucasus. The ferret's ancestors likely were encouraged as residents around granaries somewhere in the southern range of these animals 2500 or more years ago and gradually were tamed for vermin control and hunting. Thus ferrets have been associated with man not as long as dogs, but perhaps as long as cats.