Mustela vison

• The American mink remembers objects better than ferrets, skunks, and domestic cats. In an experiment from the 1960s, its ability to recognize and choose objects from memory was rated as excellent.
• The American mink is closer to martens than to the European mink. Previously, it was thought to be closely related to the European mink, but new studies show it is closer to martens than to weasels.
• The development of mink kits is very rapid; in the first 40 days of life, their weight increases 15–20 times. Milk teeth erupt on days 16–25, although the kits are still blind.
• The baculum of male American minks has a special structure with a hook at the end and a collar resembling a rapier handle. The baculum of males is significantly larger than that of the European mink.
• The American mink is less demanding of habitat conditions than the European mink. It lives in streams, lakes, large rivers, islands, and coastal areas.