Reminds me of my son when he was about five.  He was always crawling up on something and my wife and I kept scolding him and telling him he was going to break his neck.  One day he was in mamma's flower bed just a diggin' a hole.  She asked what he was doing and he said building a mouse trap (we had one get in the garage a week earlier).  She asked how it was going to work.  He said the mouse will fall in the hole and break his neck!