My cousin's yorkie, Bosley, used to climb the baby gate she put up when she left him at home, confining him to her short wood-floor hallway. She came home one day and he was out. So.......she added another baby gate on top of the first one, making it twice as tall, because she figured he was just jumping over it. A few days later, she came home and he was out. Not to be outdone, she put a THIRD baby gate above the first two, leaving only 6 inches from the ceiling. She thought she had him beat, but nah........it took him a few weeks, but eventually, he got out. She finally had to set up a camera to watch him and saw that he was CLIMBING the gates and getting out. Little stinker!
They're sometimes too smart for their own good!