Nail biting: why it happens and what to do about it (ages 3 to 4)

Why preschoolers bite their nails

Your child may bite her nails for a number of reasons – out of curiosity or boredom, to relieve stress, or from force of habit. Nail biting is the most common of the so-called "nervous habits", which include thumb sucking, nose picking, hair twisting or tugging, and tooth grinding, and is the most likely to continue into adulthood.

Nail biting is often a way of relieving the intense but passing tensions of childhood. All children get anxious. Learning something new at preschool or feeling shy at a party or on the playground are common triggers. If your child bites her nails primarily at times like these, it's just her way of coping with stress or comforting herself, in which case you have nothing to worry about. It’s likely that your preschooler will eventually stop on her own, but if the biting goes on longer than you'd like, or if it's a habit you just can't abide, there are simple ways to help her quit.

What to do about nail biting

Address her anxieties
It's essential that you deal with the underlying causes of her behaviour and think about whether there's stress in your child's life that you need to address.

If you have an idea about what might be making your child anxious – a recent move, a divorce in the family, or a new preschool, for instance – make a special effort to help her talk about her worries.

Don't nag or punish
Unless your preschooler really wants to stop biting her nails, you probably can't do much about it. Like other nervous habits, nail biting tends to be unconscious. If your child doesn't even know she's doing it, nagging and punishing her are pretty useless. Even adults have a terrible time breaking themselves of habits like this – and most parents, when they think about it, realise that they regularly display such behaviour. (Be honest: do you tug on your ear or twirl your hair while you talk on the phone?)

In general, though, as long as she's not hurting herself and doesn't seem overly stressed out, your best bet is to keep her fingernails neatly trimmed to lower the temptation to bite off ragged tips, keep her hands clean to cut down her exposure to germs, and try to keep her attention focused elsewhere. If you pressure her to stop, you'll just be adding to her stress and risk intensifying the habit. And any direct intervention before she's ready to stop – such as painting bitter-tasting solutions on her fingernails – will feel like a punishment to her, whether you mean it that way or not. The less fuss she associates with the habit, the more likely she is to stop on her own when she's ready.

Help her when she wants to stop
If your preschooler's friends are teasing her about her bitten nails, she may be ready to stop – and she'll need your help. First, talk to her about the teasing, encouraging her to tell you how it makes her feel. Reassure her that you love her no matter what her nails look like. Then move on to possible solutions.

Talk about breaking habits
Begin a discussion with your child about what nervous habits are and how it's possible to break them. A good book to read together is What to Do When Bad Habits Take Hold: A Kid's Guide to Overcoming Nail Biting and More by Dawn Huebner and Bonnie Matthews.

Help her become aware of the habit
Encourage your child to become more aware of when and where she bites. Agree on a quiet, secret reminder for times when she forgets – a light touch on the arm or a code word. Suggest a substitute activity or two (a puzzle toy for car rides, for instance, or a smooth stone to hold while reading) and then practice the alternative habit with her for a few minutes before school or at bedtime.

Some children benefit from physical reminders that call their attention to the habit the moment they do it. This option is helpful as long as your child is the one choosing to try it; if not, it'll just seem punitive to her. Try keeping band-aids on her fingertips or colourful stickers on her nails, or applying a bitter-tasting solution designed to help people stop biting their nails, which is available in most pharmacies. Check with the pharmacist which product is safe for your child.

Different children prefer different techniques, but in general the more your child feels like a partner in this endeavour, the more likely she is to succeed – and the better chance you have of avoiding a power struggle.

When to worry about nail biting
In rare cases, severe nail biting can signal excessive anxiety. Consult your child's doctor if she's biting her nails so intently that her fingertips are sore or bloody, if her nail biting is accompanied by other worrisome behaviour, such as picking at her skin or pulling her eyelashes or hair out, or if her sleep patterns have altered considerably.