As I'm reading this I have a big smile on my face.  I had the same trouble
and out of the blue I read somewhere that some ferrets do not like the
pellets(type of litter).  So I went to the store and purchased Carefresh
Litter.  It looks like some kind of processed paper bits.  Leave feces in
the box, and I had to scruff my little girl several times for playing nose
dive until the boys had urinated in the box.  Then the scuba game was
over.  I have hardwood floors so I use double sided tape to hold my house
litterboxes down and twistties for the stuff in the cage.  Note: My girl
will try to clean the litterbox out when SHE thinks its time for a change.
I clean them daiily but sometimes this is not enough for her.  Also if she
thinks its too dirty for her she will go right beside the box and make sure
that I am looking right at her before she does her business.  But give
changing the litter type ( I think carefresh is used as bedding by some
people also) I use it specifically for litter only.20.00 for a 50lb bag.
lasts me for a few weeks.  I onlu use enough to cover the bttm as they
get changed every day!  Best of Luck!!!
 
Peiko, Ghengus, and Loki
Matt and Ron
[Posted in FML issue 3099]