I have a two story house where the living room is open all the way to the second floor ceiling. I have an open staircase that goes up with banisters and railings. The cats love to play upstairs on these banisters. Puffy (3.5 months old) was playing up there the other day, and Doug and I were watching TV. Doug says "That cat's going to fall and die one of these days." What do you know, not two minutes later, Puffy slipped, fell, landed on his feet, shook himself off, and looked at us like, "You know, I did that on purpose." Then he calmly walked off into the other room. Cats!