The human mouth is in the midline of the body. We have talked about how the midline of the body is the place where you bring hands together for calming. See Magic of Midline for more.

Anything that runs in the midline from head to toe is an area that is highly sensitive for information gathering and for calming. So, now you know why baby may dislike you touching his nose, belly button, diaper area, etc.

When your baby first learns to put his finger to his mouth it is considered a developmental milestone in infant assessments. Sucking is one of the major ways he can learn to calm himself. That is why it is very important to allow a baby to suck the breast, the pacifier, and his finger for a soothing experience. We have always known that a child needs nutritive sucking while feeding. What research has discovered over the last thirty years is that a baby, child, even an adult need a certain amount of nonnutritive sucking as a self calming tool for the central nervous system. Sucking is a form of oral motor stimulation. You probably have adult friends who suck and chew on straws or suck on cigarettes. Some individuals need more sucking than others, but it is definitely a part of being a human.