Ch4rlie, I've heard of ferrets being biters but have never come across one. The two that I have hardly ever even put their teeth on me, even when playing. Tapal, the one in the picture is very hyper and nipped a bit at first but a little proper training let her know when she was doing it too hard. And, no, "proper" training does not include punishment. What I've found helpful is not to pull away when they latch on and, in fact, push towards them instead. It's hard to break that instinct to pull away but I've found this method effective with other kinds of animals, also.