A ferret , the domestic ferret ( Mustela putorius furo ) , is a small animal from the Mustelidae family . Several other Mustelids have the word `` ferret '' in their name , but they are not the same . Several other small , elongated carnivorous mammals belonging to the family Mustelidae ( weasels ) also have the word ferret in their common names , including an endangered species , the Black-footed Ferret .