At this age, Mack constantly studies my face from different angles and wants to touch it at every opportunity. His new favorite is sticking his fingers in my mouth or grabbing my nose (those little fingernails hurt though). This is his way of learning more about me and testing the fact that I am a separate person from him. With games like peekaboo, he is also gaining a sense of security about loved ones who disappear and then return almost immediately. He will try to attract attention frequently if I wander away from him.
Mack is quite capable of rolling over with stronger neck and arm muscles however he never liked being on his tummy (even in the womb he refused to be face down) so we've pretty much skipped it altogether and moved on the the next milestone: sitting up, although he still needs to be monitored with occasional assistance.