The answer in this case is scruff, a full, firm well supported, I mean business scruff!
Put your hand around the ferret's neck and pull all the loose skin with you fingers and lift the ferret by that skin always supporting his bottom legs so he is not dangling. When this is done the ferret will freeze almost imobile, this is how his real Mom got him to listen and he will remember this for the rest of his life.
Now it's your turn, only scruff when necessary or it will loose its meaning to the ferret. "Wow, am I having a good time! I'm running around bumping into things, exploring, play fighting and really playing rough with my humans. But why are they getting mad I don't know what I did?"
Does this sound like your ferret nipping or biting too hard? Are you causing the problem by getting him a little too wound up? They are electrified jello. Is he running up to you and biting maybe to get attention? Could he just be biting because he doesn't know what else to do? His cage mates didn't mind, but you do.
First assess the situation and try to pinpoint why and when. You are his Mommy or Daddy now and you would have to do what any good Ferretmom or Dad would. The moment he bites, scruff him a tight scruff supporting his bottom. Face him and say in a very firm loud voice "NO"!
Sometimes a little loud hissing and growling will also help. Just make sure no one else is around when you hiss or growl. Immediately put him in his cage for a time out. This should be no longer then five minutes, even this is past their attention span. You must keep this up and it must be the same each time done immediately after his bite. If you wait too long he wont have any idea why he's being punished. If he's nipping too hard and you want him to stop, try pushing your finger further into his mouth, GENTLY, he'll immediately let go and you will scruff as above.
If he has you in a way where that is difficult, try putting your free fingers around his face and GENTLY apply pressure, this should make him let go, and once again scruff as above.
Now I know they're little Houdini's but he can't get both hands at the same time, so if neither of the above methods works try this, but once again very GENTLY tweak his whiskers, scruff him and put him in his cage.
One of these methods should work especially if you are dealing with a younger ferret that has not been abused by humans, ignored by humans, or is afraid of humans. These types of ferrets need special help which is not covered here but will be covered later. As with most animals and humans, rewards work. When he is being good reward him with a small treat. When you see him getting too wound up, back off the play and give him a treat. This will quiet him down immediately. "Ah got my raisin gotta go." By the time he comes back he'll have forgotten what he was doing.
If he gets nippy the minute you start playing with him use something other then your hands. A game of tug of war with a towel would be a good idea. He just got out of his cage and is fully energized and just wants to make the most of it, but you have to show him how. Try to think of things from his perspective, ferrets just want to have fun and the more he does while being good, the less bad he will do, because he will learn being bad is no fun.
All the things you want to teach him will take time and patience on your part, and a lot of repetition. He may catch on right away or it may take several weeks.
The easiest place to train is in a small confined area where a lot of one on one instruction happens. If you have a room full of people don't try to train him there, to much excitement and distraction won't do either of you a bit of good. Just remember time patience and love, and the end results will be worth every minute.
Lay the fur face on his back and put some Ferretvites or Ferrettone on his tummy. It's easy if you lay him on your lap. This will keep him busy as you clip his nails.
If you do this in a well lighted area you will see where the vein in the toe nail is, clip below this. I cut my furries nails about a 1/ 4 inch below this.
Should you nick this vein he will be bleed. Have the liquid syptic handy, apply the liquid syptic and hold it against the nail with a cotton ball, the bleeding should stop shortly.
I like clipping the nails prior to bathing, that way the residue of the ferretvites on the belly gets washed off. Otherwise just use a wash cloth and wash his tummy off. ferretvites taste good but they sure are sticky.