my 5 year old daughter is biting her nails too much. I tried talking with her nicely, tried anti biting nail polish and some bitter tasting things on the fingers, but nothing worked. she bites most during watching tv, but nowadays she is not doing that. so I thought it stopped, but nails are still not growing. now I noticed a video which her class teacher shared, in that video she was biting nails. how to stop this habit