Nail biting not only looks ugly, but can injure the nail matrix and lead to infection. Shape magazine tells readers how to break the biting habit.

The magazine suggests getting a weekly manicure for a month to clean up torn edges and hangnails, and well-groomed nails might prevent further biting. Apply a hardening topcoat daily, such as Butter London Horse Power Nail Fertilizer, to keep nails strong.

Also try painting on bitter liquid such as the I Quit nail biting-prevention pen or using tea tree oil.