Third, you're inviting fungus, bugs and bacteria into your system. Your exposing your mouth and gums to infection and the consequences are not cool. Trench Mouth, Tapeworms and Pinworms are just a few whose larvae ingestion are attributed to nail biting. They can grow to a few feet long and actually live in your stomach. Think of all the times you touch a door knob, computer, phone, locker, remote control, pet an animal or open a car door without washing your hands.
Nasty beasts reside.
Decide you're going to. It only takes 21 days to break a habit. Make a pact with yourself. Enlist the support of friends and family. Don't get angry when they let you know you're slipping.