I have a ferret that doesn't like raisins, either!  Other than his TF, all
he'll eat is banana - not banana chips.  As a matter of fact, the banana
has to be "just right" - if it's not quite ripe enough, or too ripe, he
doesn't want it.
 
Over the summer we got a sandbox for our ferrets.  They loved it right away
(we never had a problem with them using it as a litter box), but one of our
ferrets always ends up getting carried away and getting sand in his mouth.
That, of course, spoils his fun, and he won't go in it again for several
weeks.
[Posted in FML issue 2470]