COMMON BEHAVIORAL DISORDERS IN PEDIATRIC NURSING Explain/Define Nail biting Nail biting is also called onychophagia. Nail biting is the most common bad habit of school going children. Which is mainly found in children above 4 years. It is a common habit in which a child engages in repetitive biting and chewing of his fingernails or toenails. Nail biting is often caused by stress, anxiety, boredom, self-punishment, nervousness. Nail biting can