Stop the tapping.  Times out work wonderfully.  Be consistent.
 
Here is an EXCELLENT site to help you:
http://www.geocities.com/SoHo/Lofts/1083/probindex.html
 
I don't personally hold with any of the choking or physical punishment
approaches some folks use.  Steve and I have had ferrets in our family
going on to 23 years and we've found that ferrets love to please, so
shaping their behavior toward what you want with very active
encouragement of good behavior and times out for bad behavior is the
best way to get trusting ferrets who are gentle as can be.  (There are
sometimes some exceptions among rescues who have had a very hard time
so they aren't always as gentle as others.)
 
Has the ferret had the first vet exam?  Kits need several over several
weeks.  They need to make sure that teeth are erupting properly (not
doing so can lead to biting), get general health checks, and provide the
series of kit canine distemper vaccines and later the rabies vaccine.
It is also important to find out if the ferret has a handicap which
allows her to be easily startled such as deafness of blindness.  What
are the markings?  It's important to know that blaze heads, and white
heads have much higher rates of deafness.  When a handicap is present
other training methods are useful and there are past posts in some
websites like Rebecca's, and in past posts in archives like
http://listserv.cuny.edu/archives/ferret-search.html (Ferret Mailing
List) and
http://fhl.sonic-weasel.org (Ferret Health List).
[Posted in FML issue 4517]