He'll find something else, believe me. kids can get into a mess in nothing flat.
I'm reminded of a time when I was 5 and my brother was 3. The parents had just gotten us cleaned up and dressed to go visit some relatives, and told us to play outside and stay out of trouble while they "got ready". I think they were knocking off a quickie. When they came outside to get us, they found us litterally swimming in a big mud puddle, having the time of our lives. My old man was so pissed off he nearly beat us to death.