Rooting and sucking reflex

Definitions:

Rooting reflex

The rooting reflex is present at birth; it assists in breastfeeding, disappearing at around 4 months of age as it gradually comes under voluntary control.

A newborn infant will turn his head toward anything that strokes his cheek or mouth, searching for the object by moving his head in steadily decreasing arcs until the object is found. After becoming used to responding in this way (if breastfed, approximately 3 weeks after birth), the infant will move directly to the object without searching.

Sucking reflex

The sucking reflex is common to all mammals and is present at birth. It is linked with the rooting reflex and breastfeeding, and causes the child to instinctively suck at anything that touches the roof of their mouth and suddenly starts to suck simulating the way they naturally eat. There are two stages to the action:

1. Expression: Activated when the nipple is placed between a child's lips and touches their palate. They will instinctively press it between their tongue and palate to draw out the milk.
2. Milking: The tongue moves from areola to nipple, coaxing milk from the mother to be swallowed by the child.

Definition source: http://en.wikipedia.org/wiki/Primitive_reflexes