My 4 month old CAG nibbles my fingers quite a bit when I'm holding him on my hand. Sometimes, when he gets excited, he nibbles quite hard and I'm not sure how to stop this behaviour. I try to distract him with a toy when possible, or say "ouch" and drop my hand slightly to stop him. Is this normal? Like teething and will happen less as he grows? Is there anything I am doing wrong or should be doing to train him that biting hard hurts!! Thanks