Our two cats and two ferrets have shared the cats' litter box from Day 1 (2
years ago).  The ferrets have their own in the cage, but prefer the cats'
when they are running around.  Just this week we moved the ferrets into a
HUGE cage (custom-made by the Jester Rabbit Company) and now the cats get
into the ferrets cage every time the door is open and use the ferrets'
litter box.  Oh, well, turn about is fair play!
 
On a slightly different subject, one of our cats was a kitten last summer.
She loves to play with our sable ferret.  With direct supervision for about
6 months, cat and feret learned to be gentle and now can be left alone with
each other safely.
 
Janice; Kitzka and Sweetheart (ferts); and Shadeau and Boots (cats) from
Boise, Idaho
[Posted in FML issue 2367]