Yesterday I had to paint the west side of the house. So I set up the ladder and let John climb up with me behind him. He climbed up several times, making believe that he was Pickles the cat rescuing a kitten from a tree. We positioned the ladder in front of the kitchen window, so that Mama could see John climbing.
After a while we came inside for a drink of water. Without my realizing it, John slipped out the front door. Next thing we knew, there was John in the window, climbing up the ladder by himself.