Well if nothing but some encouragement, I have an 8 yr old who is almost 9 who is the same way. He always has been. I used to have the biting the nails habit but it seems so much more than that. My son has a lot of energy and one fo those that is always moving around. It is like a continual letting him know when they are in his mouth, he does it without even thinking. We have talked to him, taken away things like gum adn stuff until we see some nail on his fingers. It has worked some but still workign on breaking the habit. I think eventually he will. I just feel so naggy having to tell him all the time. If I see that he hasn't been doign it much or his nails are grwoing, I point that out. When they ehar teh praise it helps them to break the habit too. If you get any ideas that work, please let me know too!
D.