Nail biting, also known as onychophagia, is a common habit where individuals bite their fingernails or sometimes toenails. This behavior often begins in childhood and can continue into adulthood. It is frequently associated with feelings of anxiety, stress, or boredom, serving as a coping mechanism for some people. The habit can lead to various health issues, including infections, damaged nails, and dental problems. While many people may stop biting their nails on their own, others might require behavioral therapy or other interventions to help break the habit.