Nail biting sometimes indicates Nervous Nellydom, but not always. Your child may start by innocently trying to nip away a hangnail; the nibbling can cause soreness, which draws her attention back to it. Genetics may also play a part. One 2005 Japanese study found the nail-biting tendency was more commonly shared by identical twins (who have all the same genes) than by fraternal twins.
The substitute: Munching on pumpkin seeds or dried fruit can satisfy the gnawing impulse. You can also give your child an emery board so she can gently file away when her nails call her name.
Also try: Protect the nails by covering them with cool neon bandages during times when she nibbles (such as on long car trips). Keep fingers busy with clay or Lego pieces. It can also help to give her hands soothing attention with a scented lotion. Or offer her a special salon manicure if she can grow out her nails.
More drastic measures: If nail biting is causing infections in the cuticle or comes on suddenly after a stressful event, like a move, consult your pediatrician. Relaxation techniques (see our guide on how to manage your child's stress) or even hypnosis can help.