So a few minutes ago I was making a sandwich for one of the boys and I see him crawling by with his brother riding on his back.  It soon got quiet, which is never a good thing with two energetic boys.  I just walked into the living room and both the boys are sprawled out on the floor, looking less alive than they did twenty minutes ago.  But no worries, I asked them to raise their hand if they were still alive and they both did, so my job is still secure.  They said they're playing 'mechanical bull'.
Never a dull moment.