Some babies are born with a sucking urge that is a normal until the age of 3 and a half years. From the age of 3 onwards, we slowly start talking and encouraging the child to stop this habit. We praise our child a lot for the few minutes he/she managed not to suck his/her finger, avoiding to reffer to the hours he/she still uses it. From 4 years old on, we can use a special nail varnish that has a bitter taste and that we can find in the pharmacy, to "remind" the child not to put the thumb in the mouth. Under no circumstances, should we punish the child. If by the age of 4 and a half, there isno improvement, we can ask the pediatric dentist to help us. The age of 4 years and a half is the critical age to stop and beyond that, the habit becomes more and more difficult to stop, even with the aid of the pediatric dentist.