Your baby is five weeks old. His greatest pleasure at this age seems to be to suck. If his pacifier is not there, you’ll find him sucking on his thumb and fingers.
He’s also becoming more vocal now as he expresses himself with gurgles, coos, and hums. It’s important that you respond—by now he not only recognizes you and your voice, but also lets you know how much he likes having you around by relaxing and smiling in your presence.