How many of us on here have had ferrets with genuine 'issues' that could never be tamed? There's too many bunny huggers on here who's ferrets have never been near a warren that always protest that every ferret can be tamed but that's nonsense. Some are just temperamental regardless off upbringing, feeding, hormones or handling the same as you can get dogs or cats which bite for no reason.
The worst I've had was a hob who was really soft at home but an absolute psycho if you tried to pick him up when out hunting.