Cats are very aware of their surroundings. Put an open box in the room and invariably one will hop in it. If it is big enough, you may find two or three cats in it. Put a new chair in the dining room a cat will, also, jump on top of it. Any physical change in the room the cats become immediately aware of it and have to investigate it and explore it. Put a bag on the floor and one eventually finds it and goes inside it. Cats are always found in the oddest places.