M.J.
Unfortunately I don't have any advice for you since my husband is also a nail biter and it drives me nuts as well!!! Our 3-yr old daughter has recently developed the habit and bites her nails down as far as she can and when I asked the doctors office for any advice they said try to distract her whenever she's attempting to bite her nails which isn't really working well ... and they also said she probably picked up the habit from watching someone else do it which I'm pretty sure was her daddy. If your child(ren) haven't picked up the habit yet maybe share with your husband the fact that he could pass it on ... although that didn't work well with my hubby.