Information was obtained from 600 parents of their childrens' daytime and nocturnal sucking habits from birth. Most children used some form of supplementary sucking which commenced at birth and lasted for as long as two years. From the second year, the predominant form of supplementary sucking involved a thumb or finger and digit suckers mostly did not suck a dummy or a bottle teat at night. Palatal or arch distortion occurred in only 18 children. This was 17 per cent of the digit sucking group. It was found that of children of the 17 parents who would not allow a dummy, 10 became digit suckers. Of the 72 children who refused a dummy, 38 became digit suckers. Parents should encourage dummy sucking in children who show signs of being potential digit suckers to prevent a digit sucking habit from arising. Where a dummy was not allowed by the parents or used by the child, 56 became digit suckers.