I love it when my boys get creative. They'll close themselves up for hours and all you hear is giggling, banging, bouncing, slamming, screaming, etc. You never know what they'll emerge with: a show, something they've built or drawn, a story they've written, or now..... a video.
I thought this one was pretty hilarious from a couple of homeschoolers who don't have a clue what "homework" is. (That's the "Arthur" soundtrack playing)