Most ferrets enjoy some fruits and vegetables.
Although they're not necessary for good nutrition if you're feeding your pets a high-quality cat food, small amounts of these won't hurt. Just be sure you don't fill your ferret up on fruit, since he'll need to eat his regular food to get the required protein. Too much of nearly anything can be harmful, so try to vary your treats. Try feeding your ferret pretty much anything, in small pieces. You never know what yours will consider a fabulous treat.