Rattles have been around since ancient times, and it's no wonder: Babies love to watch and listen to these percussion instruments.

Appropriate for: Newborn to 3 months
Skills developed: Auditory
What you'll need: A rattle

While your baby is lying on his or her back, hold a small rattle in front of his or her face and shake it gently. Move it to one side and shake it again, and then do the same on the other side. Your baby won't yet be able to track it with his or her eyes, but he or she will notice the change in location, and it'll certainly get your baby's attention (try not to make it too loud – that might be scary).