My son aged 9 has recently got into the habit of biting his nails, like all the time. I find it disgusting and it's making his hands look so grubby and horrible. This habit only started within last couple of months. Never used to do it. Think his got the habit from a couple of other family members who do it. I've always encouraged him to take better care of his appearance and hygiene. Not only that, I find it awful to see/hear/watch. Any other parents feel my pain?