Infants show many reflexes as soon as they come out of their mother. Two of them are the sucking reflex and the root reflex. The root reflex is when the baby's side of the mouth is touch and they will then move their head towards where the were touched, allowing them to latch onto the breast or the bottle for food. The sucking reflex pretty much explains itself. When the roof of the baby's mouth is touched, they will begin to suck as they will think/know that it is feeding time.
Hope this helps!! Other reflexes can be found on: http://www.stanfordchildrens.org/en/topic/default?id=newborn-reflexes-90-P02630
