I found that just abouot the only bahaviors I found that really needed
corporal punishment in a ferret where excessive biting, rubber/foam/cable
chewing, and backing right up your feet to leave a ferret bomb.
 
I found that for biting either a nip from me on a fold of skin, or a good
pinch ONLY when she bite painfully hate when not playing (such a biting me
when I'm sleeping) got her stay within limits.
 
Still still nips at annoying times, but never hard, just like an invitation.
 
Other times I found that picking her up and hissing at her, or pinning her
on her back and hissing at her worked well when she forgets the pack
hierarchy.
 
Spanking just does not work.  Too hard and you hurt them, too soft and they
think it is play time.
 
Picking them up by the scruff of the neck, hissing, and putting them in the
cage or just holding them still for a bit seems to get that your upset thru
to the ferret mind.
[Posted in FML issue 1642]