In the last week Edward has discovered a whole new purpose for his rolling - to enable him to rock! And he hasn't been holding back.

Pretty much the moment you leave him, he'll put in just a single roll to get himself onto his tummy and then he'll be straight up onto all fours.

He's yet to actually manage to move anywhere, but he's certainly very keen on rocking on the spot. He's now able to do this for several minutes at a time before he finally lets himself collapse back to the floor. However it's normally only a matter of seconds before he's back up and trying again.

Here he is rocking away last weekend...

So how do babies know to do this? We've certainly encouraged him to play on his tummy, but we've never shown him how to rock. Apparently all babies do it for a while before crawling as a method of strengthening their arms. But how do they all know they need to? Edward seems to know that he wants to go somewhere (understandable when that toy is just out of reach), but how does he know that rocking on the spot will eventually help him to accomplish movement?