Time for new toys?

I think boys are born with a need to push things around. I would love to read a study or a theory as to why this is. There has to be a reason other than they want to push toy cars around. Oliver's need to push is coming on strong. He will push anything he can get to move. He pushes all over the room and into the next. His latest choices, in order: a broom, a bag of pasta, and not pictured the dust pan and dust broom. He gets really mad when the broom gets up against the wall and he can't push it anymore so I have to turn it around. I think it's time for some new toys!!!! Don't worry baby boy, your Tonka Trucks are on their way!