The ferret – Mustela putorius furo – is a quadruped, weasel-like mammal belonging to the family Mustelidae.
Derived from the Latin ‘fur’, meaning ‘thief’ – hence the cognates ‘furtive’, from ‘furta’, ‘theft’, as in Patrick Geary’s superb study of the trade in stolen holy relics, Furta Sacra – the name raises some questions: presumably it’s the animal’s ferrety manner of flushing out rabbits from their burrows and killing them. And of course there’s the metaphorical expression ‘to ferret [something] out’, which has connotations of furtive, crafty, insidious and determined behaviour, characteristic of the animal.
According to Wikipedia, ‘When excited, they may perform a routine commonly referred to as the weasel war dance, characterized by a frenzied series of sideways hops and bumping into things. Despite its zeal, this is not aggressive but is a joyful invitation to play. It is often accompanied by a soft clucking noise, commonly referred to as dooking’.