Have your children wear helmets as soon as they start to ride tricycles and if they are a passenger on the back of an adult's bike. If they learn to wear helmets whenever they ride tricycles and bikes, it becomes a habit for a lifetime. It's never too late, however, to get your children into helmets. Allow your child to participate in choosing their helmet. They'll be able to let you know if it is comfortable. And if they like the design, they are more likely to wear it.