I am wondering if anyone has a suggestion for my four year old. He is alway biting on his nails and now he's chewing on things like toys and pretty much anything plastic. He destroyed a tupperware lid and some toys. Some people say it could have to do with stress; but I think he just has a bad habit. He used to suck his fingers but after two years I finally got him to stop this past Spring. Unfortunately, his father chews his nails sometimes and he saw him doing it one time and never stopped. He literally has chewed his nails all the way down, and he still bites them! My question is, do I keep on him about it or should I just buy him something to chew on that won't ruin his teeth? Any suggestions would be greatly appreciated.