How do they learn?

This is just a short blog on little things a 2 year old will do. As I posted a while ago, a quiet house isn't always a good thing. Once again, it got a little quiet and when I found James, he was hiding something behind his back, a salt shaker. He's fascinated with the salt and pepper shakers and have to put them on everything he eats. AND he has to do it himself. So, apparently, the vents looked like they needed some flavor......No major harm done. But when do they learn to hide something behind their back? Maybe the same way they hide their eyes when they're trying to be sneaky or not do something.