Our best success with the type of biter you described was consistency and the
scruff and shake method.  Be sure you don't set the ferret down right away.
 We've had many turned into us where that has apparently happened and all it
taught the ferret was ' If I bite hard enough, I'll get set down and I can go
about my business."  I have a couple of deep puncture wounds on my wrist
right now from one of them, but he's getting better.
 
Just continue to hold it after the scruff and shake and shout of "NO" in its
face.  Talk gently and reassure it that you do love it.  Keep a few bandaids
around too , because some are really stubborn, but every one of those
eventually became a great, great lovable ferret.
 
Dick Bossart
[Posted in FML issue 1162]