Prevention of nail-biting.. reduce the levels of stress and anxiety. Preoccupation actively useful and make the edges smooth nails

1) reduce the levels of stress and anxiety when the child howsoever caused my body, environmental or myself. 

2) fill the hands of the child actively makes it useful for an email to practice this habit. 

3) Make the child's fingernails always cropped well and make it smooth without the rough edges.