Rub rub rub! We’re transferring electrons, classic fun.
It sticks! Now here’s a lesson in the danger of correlations being construed as causations: If Milo roars, the balloon falls. He thinks his roar CAUSES the balloon to come down. Right, like Mommy making tea causes the day to start.
Give It A Burl 
Well, my educated guess from years of experience is that about 2/3-3/4 of adults also don’t understand the difference between causation and correlation, or coincidence, for that matter.
Amazing childhood fun & so will be the light in his eyes when his brain understands it all.
Want more does a little man have if not his roar? At least he didn’t think to try throwing his breakfast at it. Not yet at least!