Wow, now I'm one of the ones answering posts about this instead of
asking the biting question...  Ultimately, I found the most successful
means of discouraging biting with my ferret Amelia was the time-out
method.  I'd scruff her, give her a serious talking to for a few seconds
and make her stay in the cage until she stopped rattling the bars and
stopped trying to bite me when I reached in to lift her out.  Nose-
flicking, pinching, or scruffing without being put back in the cage all
just made her mad-- she is a ferret with a strong sense of personal
vengeance, although she loves just as strongly. Amelia was not as
fierce as some of the ferrets mentioned here recently sound, but she
frequently drew blood.  She still at 9 months occasionally does, but it
seems to be accidental for the most part, unless you're trying to take
food away from her.  So, patience and time outs, and use extreme caution
in letting the ferret near your face if it still regularly chomps the
rest of you.  I nearly got a pierced nose courtesy of Amelia.
 
Regina and Amelia (Mom, you're just not cool enough to be seen with me,
how about a nose ring?)
[Posted in FML issue 1284]