A Baby's Reflexes..A baby is born with certain reflexes to protect them during the first few weeks. These reflexes will disappear after a few weeks and be replaced with voluntary movement during baby's development.Doctors will check these reflexes to ensure his central nervous system is working correctly.Walking Reflex
If you hold baby in an upright position with his feet touching the floor, his legs will seem to be trying to walk. This reflex will last for about 3-4 weeks, and he won't actually.