It just depends. I would think by 5 1/2 months he would at least be trying to roll (one way or the other), grabbing things with his hands and trying to get them in his mouth and being awake, more attentive. He should be able to sit in your lap with minimal support, too. But it really varies. My 5mo is rolling all over, pulling himself with his hands to try and get his toys, shaking his rattles, putting his toys in his mouth, exploring his hands and feet. Today he figured out how to hold his own bottle while he's eating. He isn't crawling or sitting (without help). He's my 5th and each one was a little different. My older son was crawling up the stairs at 5 1/2 months. By 6 months he was pulling up on the furniture and cruising around (walking while holding on to things). He was a handful.
at 8:09 PM on Dec. 21, 2010