Your baby ferret may not be biting out of aggression. Kits (young ferrets) bite because thatís how they play, and they havenít been taught the difference between play biting and real biting yet. When left with other ferrets and their mother, their siblings and mom will teach them that this is not acceptable but since you do not have that luxury and it is only you and Mr. Nippy, then you have to teach them yourself. The key is patience and persistence.
Here are a few ways to teach your ferret not to bite:
1) When your ferret bites you, scruff it gently but firmly and drag it on its back across the floor. This will show it that you are the dominant one, and it is the way that a mother reprimands her kits.
2) Try forcing your finger further into its mouth when it bites you. Do not shove your finger down its throat, but if you push back enough it will make it open its mouth. It will also make the ferret associate the unpleasant feeling with biting you.
3) Try a time out, where you put the ferret in a punishment cage for a few minutes. This works especially well if you have multiple ferrets, and the biter can see the other ferrets still out having a good time. No more than 5 minutes however - after that point, the ferret won't know why it's being punished.
4) Cover your hands with a bite deterrent spray like Fooey so biting you tastes bad.
5) Some ferret owners have tried using kitten mittens (fuzzy gloves for playing with kittens) to teach their ferrets the difference between skin and other things. Allow your ferret to roughhouse with the glove, but when you take it off and the ferret bites your bare skin, use one of the techniques above to discipline it. This teaches ferrets that itís ok to bite the fabric, but it is NOT okay to bite skin. However, there is a chance that this can actually prolong bite training, as it doesn't allow the ferret to get used to being handled constantly by human hands.
Never EVER flick your ferret on the nose or hurt it in any way. This includes screaming at it and throwing it. This will only make your ferret fear you and might even make it bite you more because it will feel threatened by you. Just be patient and continue to use the above techniques every time your ferret bites.