Do You have a Habit of Biting Nails? Easy Ways to Stop it The habit of biting nails might look harmless but it is harmful. The habit of biting nails is called 'onychophagia' | 8 May 2021 11:12 AM GMT Biting nails is a repetitive behavior that usually starts in childhood. Many people who begin biting their nails as children, it becomes their lifelong habit. And, it can be extremely difficult to quit. Once it becomes a habit, it can become your go-to behavior when you are waiting around, frustrated, or feeling bored. You might know several people who bite their nails. The habit of biting nails might look harmless but it is harmful. The habit of biting nails is called 'onychophagia.'