Sounds like a fun idea to teach your ferret to fetch!  Mine grabs the tennis
ball, which is actually the dogs' toy, and runs off with it to her special
junkyard place.  When the dogs see her with it they run after her whimpering
trying to get the ball back.
 
I haven't had the time yet to teach my dogs how to find the ferrets yet.  I
was waiting to write you back after I tried it to tell you the results.  I
might try it tonight.  (He told me to: Let the ferret out of the cage and let
it run off.  Then get your dog to run around the house saying find the
ferret, or where's the ferret, with your dog following you.  Once you find it
praise your dog and be excited.)
[Posted in FML issue 1286]