Nail biting is one of the most common bad habits of childhood. Some children simply bite out of habit; others bite because of boredom or stress.
Believe it or not, even small children get stressed! Children deal with stressors every day that often aren't recognized by parents. Other children mindlessly bite while watching TV or reading. As long as the nail biting does not cause significant injury to the fingertips, there is no need to worry. Often, this bad habit eventually goes away on its own, but some children may continue this habit into adulthood.