Your baby's reflexes

Moro (startle) – disappears after about four months:
When infants are startled by loud sounds or by being suddenly dropped a few inches, they will first spread their arms and stretch out their fingers, then bring their arms back to their body and clench their fingers.

Tonic neck – disappears after about four months:
When infants’ heads are turned to one side, they will extend the arm and leg on that side, and flex their arm and leg on the opposite side, as in a fencing position.

Stepping (walking) – disappears after two or three months:
When infants are held upright with their feet against a flat surface and are moved forward, they appear to walk in a coordinated way.

Placing – disappears after two months:
Similar to the stepping reflex. When infants’ feet are placed against a table edge, they will attempt to step up onto the table.

Grasping (palmar) – disappears after about five months:
When a pencil or finger is placed on infants’ palms, they will grasp it tightly and increase the strength of the grasp if the object is pulled away.

Babkin – disappears after four months:
If objects are placed against both palms, infants will react by opening their mouths, closing their eyes, and turning their heads to one side.

Plantar – disappears after nine months:
Similar to the grasping reflex. When an object or a finger is placed on the soles of infants’ feet near the toes, they will respond by trying to flex their feet.

Babinski – disappears after six months:
If the soles of infants’ feet are stroked from heel to toes, infants will spread the small toes and raise the large one.

Rooting – disappears after three or four months:
If infants’ cheeks are touched, they will turn their heads toward the stimulus and open their mouths as if to find a nipple.

Sucking:
If a finger is put in infants’ mouths, they will respond by sucking and making rhythmic movements with the mouth and tongue.

Swimming – disappears after six months:
Infants will attempt to swim in a coordinated way if placed in water in a prone position.

Ocular neck – disappears after six months:
Infants will tilt their heads back and away from a light shining directly into their eyes.

Pupillary – permanent:
The pupils of infants’ eyes will narrow in bright light and when going to sleep, and will widen in dim light and when waking up.

Source: Human Development