Ferret

Domestic ferrets (Mustela putorius furo) descend from the European polecat, with mitochondrial DNA evidence placing domestication at roughly 2,500 years ago; the two remain interfertile, which is part of how researchers established the relationship. For most of that history, ferrets were kept for hunting rather than companionship -- 'ferreting' involved sending a ferret down a rabbit or rodent burrow to flush prey toward waiting hunters or nets, a practice used by the Romans and still legal in parts of Europe today.

Ferrets were also valued for pest control: after being introduced to North America, they were used extensively from the 1860s until the start of World War II to protect stored grain from rodents. Their role as working animals only gave way to their modern status as household pets relatively recently, and pet ownership rules still vary sharply by location -- California and Hawaii, for example, restrict or ban ferret ownership outright, largely over concerns about escaped animals establishing wild populations.

Ferrets are crepuscular, meaning they're naturally most active around dawn and dusk, and they sleep for an unusually large part of the day -- typically 14 to 18 hours. That heavy sleep schedule doesn't mean they need little care: most domestic ferrets are highly social and do well living in pairs or small groups, and during their waking hours they need daily supervised playtime outside a cage, generally at least an hour, to satisfy their strong exploratory instincts.

Weight and body condition in ferrets swing more with sex and reproductive status than in most common pets -- intact males can weigh nearly twice as much as neutered females -- so owners comparing a ferret's size to breed charts for cats or dogs should expect a wider range. Most pet ferrets in the US are also already descented and neutered or spayed before sale, which affects both their adult weight and their scent output.