So for a while now my baby has been lifting his feet and just throwing them to the ground when he’s laid down. He does this ALOT and does it quite hard. He does it all the time, even while feeding, dressing or even just while lying down. He also bangs his head onto stuff when he’s leaning on it, such as when he’s leant against a door or a sofa he’ll lean forward and throw himself back and bang his head and he does this repeatedly...has anybody else experienced this? My first baby never did anything like this...should I be worried?