Rolling Over: 4 to 6 months
As your infant gets better at push-ups, she'll practice reaching in that position. And one time, with a hand up, she may lean just a bit too far to one side and suddenly find herself faceup -- startled but thrilled. Eventually, though, she'll learn to turn over intentionally.
This first awkward flip is called a log roll because the upper and lower halves of the body move as one block. At about 6 months, your baby will be able to rotate her torso; her pelvis will initiate the roll, and her shoulders will follow. Turning at the waist will allow her to look around when she masters sitting and to alternate her legs and arms as she learns to walk.
Once she's on her back, your baby will kick her legs, lift her bottom off the floor, and bring her toes to her mouth -- moves that strengthen her abdominal muscles. Soon she'll master the opposite roll: Lifting her legs in the air, she may fall to one side and scramble right onto her belly.
Skill builder: Give your baby plenty of floor space and time to roll and flip as she pleases. Toys, such as a baby gym, can also enhance development by encouraging kicking and reaching.