Ahhh...the $24K question. Most ferrets can be taught not to nip if you are patient and consistant. Mike Steele wrote a great article on how to be successfull.
Much like kittens and puppies, ferret kits must be taught not to nip. Ferrets have been bred to be a pet and shouldn't be vicious or bite, but ferret play does include mock combat, and younger ferrets and kits won't know how hard they can put their teeth on you without it hurting. A ferret at play may run towards you with his mouth open or even put his teeth on your hand, however if he presses down hard enough to hurt, you’ll need to discipline him. Remember, ferrets aren't malicious; they just need to learn what behavior is acceptable. Read more...