I had to catch his rocking in action. If he is on his tummy he pretty much spends 90% on his knees. He then will push his butt up in the air where his knees are not on the ground. It will be funny if he chooses to monkey crawl instead of traditional crawling. He gets those back legs going but doesn't realize he should move his hands forward. He will reach for thing while in this position but cant simultaneously move both.