Doesn't it just figure? As soon as you finally become comfortable trimming his tiny fingernails, your little one starts biting them off by himself! Nail biting can be a sign of anxiety, but it's no cause for alarm or intervention. Dr. Baust says that, "Kids that bite their nails usually have a parent who does it as well." Mothers are often tempted to bribe and cajole their young daughters into leaving their nails alone or pull their hands from their mouths, but drawing attention to the behavior or making a child feel self-conscious will only promote more nibbling as a nervous habit. If left alone, most kids will abandon their nail chewing for more mature annoying habits like gum cracking, pencil tapping, and incessant throat clearing.
Similar to nail biting, some children relieve tension through hair twirling or sucking. It's no big deal; in fact, many girls with long hair continue to twirl it into their teens because it's simply something to do with their hands when they're studying or gossiping in the hallways. However, you should consult a doctor if your child actually pulls hair from her scalp. "This is called trichotillomania and is certainly something that should be evaluated your doctor," advises Dr. Baust.