A: Amy, it is very common for children to grind their teeth, especially at night. This is an activity that many children engage in and nighttime is the most common time for this to occur. It's also when you are most likely to hear it because there aren't other activities or noises. Most children outgrow this, and it's usually not a problem unless your child wears through the outer layers of her teeth and causes a sensitivity or exposes a nerve. You should consult a dentist if you suspect this is happening.