Here's the problem.  You have fear biters, one of the worst problems to
fix (yet perhaps the most satisfying!).  I'm sure you will read dozens of
helpful hints in response to your post, but I might as well add my top
ten hints.
 
First, decrease the amount of stimuli that impacts the ferrets.  Move
them to a quiet corner in a quiet room, away from your child, cat, and
even loud conversation.  Build their confidence.
 
Second, increase their feeling of security, which can be done in two
ways.  You can cover the top, back and sides of the cage with dark towels
(or, if they tear at the towels, by duct taping cardboard over the cage).
Also, place INSIDE the cage a small box, large enough to hold them and
bedding.  By increasing the amount of darkness, decreasing the impact of
outside movement, and providing a nest box, you will increase their
feeling of security.  Toss away those hammocks for now.
 
Third, I use the "open hand" approach.  I allow them to approach me,
rather than grabbing for them.  When I pick them up, I do not hold them,
scruff them, or even retard their movements.  This allows them to think
contact is "their own decision."  Some people may disagree with this,
but it works well for me.
 
Fourth, NEVER punish with force.  I might place the tip of my finger on
their nose and say "no!', but I do not thump, flick, scruff, or in any
way use force to make my point.  You are trying to reteach the ferrets
not to bite, so dump violence as part of your lesson plan.
 
Fifth, NEVER reward the ferret for biting.  Many people reward ferrets
for biting, usually by offering a treat to make them stop.  The ferret
learns they can get a treat by biting you, and they learn it fast!  I
offer treats as I take biters from the cage, and after I place them back
in, but not while I am retraining them.  Later, after the biting stops,
you can offer treats.  Rather, I offer bits of food on an open palm; the
same type that is regularly fed them.  They may not eat it, but they
start associating you with dinner.
 
Sixth, become the ferret's mother.  If you really want a ferret to
respond to you, groom it, especially around the eyes, mouth and ears.
When I do this, I try to mimic the soft chuckling sound by rapidly
clicking my tongue to the roof of my mouth.  It may not sound like a
ferret, but it has a calming effect.  If, when you are grooming, the
ferret tries to bite, LIGHTLY scruff them for a short moment (like a
real mother ferret would do), but continue the grooming.
 
Seventh, WHEN you are biten, replace the ferret back in the cage
IMMEDIATELY!  Ferrets really hate being confined, especially when they
can see other ferrets having fun.  No physical punishment, no treats,
just back in the cage for 3 minutes or so, then let them back out.  If
they try to bite again, put them back in the cage for another 3 minutes.
It won't take long for them to associate biting with confinement during
play time.
 
Eighth, PLAY with your ferrets.  This is perhaps the most important thing
you can do.  Pick several times during the day that you know are free,
and schedule ferret play at those times.  You will find the ferrets will
start changing their schedule to be awake then.  Follow your schedule to
the letter!  If they bite too hard, hold a toy they can bite instead.
Initiate play, rub them on the head and belly, tug their tail, and don't
worry to much about being too rough.  DO NOT postpone play, NOR skip it!
 
Ninth, let them explore their environment BEFORE you start handling them.
A ferret's first instinct is to explore their surroundings, so give them
10 minutes or so before you start interacting with them.
 
Tenth, assume you will be the target of those sharp little fangs.  Resist
the best you can jerking away (stimulates the clamping instinct), or
trying to pry thier mouth open (stimulates the fear response).  Just
place them on the floor, and let them let go.  Believe me, I know exactly
how hard this can be!  I once had a female fear biter macerate my thumb
for more than 10 minutes!  Some people try flooding the ferret's nose
with water or various oils, but many times the ferret likes them, they
drain off, or they see them as a treat.  I have discovered a very
effective material that is NOT generally seen as a treat--vasoline!  I
just smear a thick dab on their nose, and they let go within a minute to
lick it off so they can breathe.  I have had 100% success with vasoline,
and keep an open container at hand when dealing with biters.  Another
trick is to sprinkle a SMALL amount of ground black pepper on their nose
to make them sneeze.  I don't like this one because of the danger of
getting pepper into their eyes, but I know people who swear by it.
 
The point to all these hints is that a fear biter needs to trust you,
and that takes time, patience, and the willingness to accept a bite or
two.  It is not easy, it is not without pain, but it is perhaps the most
rewarding thing you will ever accomplish.  Using these hints, I have made
several fear biters into the most loving ferrets you would ever know.
 
One last comment.  Ferrets are perceptive, intelligent animals, so there
is a great deal of variation in their behavior.  Other people are sure to
post their favorite hints, and for individual ferrets, those hints might
result in a better or faster outcome.  Be flexible, and if one thing
don't work, try something else.  Don't get locked into one specific plan.
 
I am sure you have the courage, love, and dedication to accomplish this
task.
 
Bob C
[Posted in FML issue 4102]