Between the age of one and three months, your baby is becoming more responsive. He isn't sleeping quite as much as he did when he first arrived, and his curiosity about the world around him is growing rapidly. Physically, he's getting stronger and improving his coordination. You can help to stimulate your one-month-old's physical development with constant interaction and brightly colored toys.
Invest in an infant gym for your baby. Go for one with lots of interesting, brightly colored hanging toys. He may be happy just to stare at them initially, but soon he'll try to reach out and grab them with his hands and kick them with his feet. This helps to build muscle strength and improves hand-eye coordination.
Build your baby's muscle strength with some gentle exercises. Lay her on her back on your lap and move her legs in a cycling motion. Lift her arms above her head, out to either side of her body and across her chest. Clap her hands together when you sing her a clapping song like "Pat-A-Cake."
Place your baby on his front for a few minutes of "tummy time" every day. This helps to strengthen his neck and shoulders. Never leave him unattended during tummy time, and turn him onto his back as soon as he gets tired or fed up.
Help your baby explore new parts of her body now that she's beginning to realize that it all belongs to her. Count your baby's toes while reciting "This Little Piggy." Lift her hands up to touch her face to let her see and feel them at the same time.