Mink are dark-colored, semiaquatic, carnivorous mammals of the family Mustelidae, which also includes weasels, otters and ferrets. There are two extant species referred to as "mink": the American mink and the European mink.

The breeding season lasts April to May. Mink show the curious phenomenon of delayed implantation. Although the true gestation period is 39 days, the embryo may stop developing for a variable period, so that as long as 76 days may elapse before the litter arrives. Between 45 and 52 days is normal. There is only one litter per year. They may have between six and ten cubs per litter.

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