My ferrets (and dog) love Good Boy chocolate drops.  It is a synthetic
chocolate that I found in a pet store and Foster and Smith catalog in the
dog treats section.  Whenever the ferrets hear the box being opened, they
come running!  Tiger will find the box anywhere and climb anything to get
at it, so we have to be careful to put it somewhere he definately can't
get to it.
 
I found that these work as great training aids since they love them so
much!  As with all treats, only in moderation.  Tiger found out what it
was like to have a sore tummy from overindulging!!!
[Posted in FML issue 1069]