This past month, when he's not battling his crazy back to back ear infections :( he's taken up crawling with a vengeance. It's so fun to see his curiosity sky rocket as he explores the world around him. He's also just recently mastered sitting up from a laying down or crawling position, which, now that he can finally do it, has made him so much happier.
He's not completely happy just crawling around however, as he continuously tries to pull or push (think: downward facing dog pose) himself into a standing position. When we're nearby, we'll place him next to the table or couch to stand and play (even trying out his legs and taking a few steps when he can!). Only then is he truly happy.