At around 4 months

• Lying on his back, your baby explores his body by caressing his tummy or knees. He can also roll over onto his side.
• He can succeed in holding an object placed in his hand for a few moments, but then he often loses it.
• He puts his hands together and holds them tightly closed.
• He turns his head when he hears a noise.
• He starts laughing out loud.