[SABELLESMOM]

First thing is, what the breeder told you is correct. This is normal puppy behavior and it stands true for any breed of dog. 10 weeks is far too young to label it as "aggressive."

How old are your children? You may not think so but sometimes, simply what children do naturally...inadvertently elicits his playful behavior. Children like to run. Puppies like to chase. And the game is on. Children make interesting squeeling noises. Puppies thing that's fun and want to join in.

Think about how puppies play with their sibblings before coming home. Chasing, running, jumping, wrestling, and yes, biting. How did one pup let him know he was getting too rough? They yipped...LOUDLY! And moved off, or turned around not looking at him. You can combine it with diversion.

Have you tried a diversion technique? You quickly substitute a stuffed toy or ball. Having one on you or nearby makes this much more successful. You could also toss a ball or toy. Teach him to play fetch. Play hide and seek.

You can also begin training in your own home. You could teach him to sit for a treat. you can have him sit for his meal. You can start indoor leash walking. "Sit" may even come in handy when he gets excited and nibbles your fingers again. It's asking him to do a learned behavior and forget the biting.

We also used an "UH, ah AHH! No-o-o Nibbling!" to get his attention. That's the trick get his attention and divert...or simply divert. You will find, if you put your mind to it, there are many ways you can accomplish the same thing. Clap your hands 3 times? Got his attention? Say "Let's go!" and have him follow you to the kitchen. Following becomes the diversion. If you add a treat for following you from the snack bar, even better!

Lastly, it takes time. Puppies do not learn overnight. They are still infants.
I prefer positive reinforcement over negative teaching, shaking or holding him down. I find generally these methods a bit outmoded, and I don't use them, ever.