We've got 23 and 1/2 years of experience with ferrets and our work out
to be so trusting that some like to put their heads entirely into our
mouths.  Stop the physical punishment!  Go to consistent times out in
a cage or carry cage when the kit screws up.  This is the single best
technique we have ever found.
 
Also, since he is a kit have his teeth checked during his regular vet
appointments for vaccinations in case there is a problem related to
dental eruption gone wrong, and get him one of these SAFE teething aids:
Cheweasels, Foamy Fries, or Marshall Chews.  All of those are made of
dense gelatin so while they can cause a bit of GI upset if a ferret eats
too much at once they do not cause life-threatening blockages unlike many
of the dog teething aids or toys when used by ferrets.
 
Ferrets will do just about anything to please their humans, but they also
can get stubborn, too, so physical punishment has a strong tendency to
backfire.  On the other hand encouraging good behavior with loads of
praise, cuddles and sometimes treats, and showing a ferret that bad
behavior get it ignored (in the cage or in the carrier) works wonders.
Besides, if you inflict pain with your hands you teach that hands are to
be feared and fearful animals are more likely to be defensive, and you
teach teach that hands and pain go together so maybe they will naturally
figure that means it is acceptable to give what they receive.
 
Face it, kits, puppies, kittens and even baby sisters (or brothers) DO
bite for a while till they learn that it doesn't tend to work out to
their advantage, but that not biting does work to their advantage.
 
DO be consistent and patient.  Steve isn't as persnickety as I am on
that score and I never get a nip whereas he on rare occasion will.  Many
people tend to think of animals as stupid, but when you consider how
rapidly most domestic animals learn to live within a different species
(ours) rules and how bad humans are at even meeting other animals
half-way a person really needs to do a bit of re-considering of who is
the faster learner.  :-)
 
D, I have not read anything to indicate that insulinoma is the leading
ferret health problem in terms of rates, nor above the rates of adrenal
neoplasias.  Is your area experiencing a recent upturn which your vet
mentioned that has changed rates there, has it just been discussed
recently a lot in some fora in which you participate (Mentions do tend
to appear in clumps because people join in.), or did someone else say it
(in which case, please, ask the person for the source), or do you have
a journal article I need to see (in which case I really, really would
appreciate if you would post the journal name, number/date, author(s),
etc.
 
>One of my ferrets, Tabitha (now an Angel) was at one time Insulinoma
>(Hypoglycemic); however, she somehow swung to diabetic and I was giving
 
That on rare occasion will happen even without surgery (and temporary
diabetic range glucose levels after surgery are not usual).  I don't
have the time to look it up right now but I think that either Dr. Bruce
Williams or Dr. Jerry Murray (maybe both, or perhaps a different vet or
location?) wrote to the ferret health list in the past on how this can
happen.  I don't have the time to search right now, but you can find the
easily searched FHL Archives in http://fhl.sonic-weasel.org .  If I were
doing that search I would begin by searching for diabetes in the content
and the from containing williams or AFERRETVET.  Another possibility
might be a past Ferrets article of Dr. Williams and you can find the
ones which appeared 6 months or more ago in
http://www.afip.org/ferrets/index.html
 
Imitation is the greatest form of flattery.  I LOVED the story about the
ferret who tried urinating while standing up in the sick in imitation of
his Daddy!  The weirdest imitation we have encountered was when Hjalmar
tried belly dancing while Steve was holding him upright because I was
working on my helices.  That was a LONG time ago.
[Posted in FML issue 4717]