I recently bought a new puzzle, and my cat loves to sleep in the puzzle box that doesn't have peices in it. It's so funny-He's a 15lb cat and sleeps in this tiny little puzzle box. I put the puzzle in the other box and put it up, and left the empty box on the floor for him. He also has a baby blanket he considers his. Sometimes he will take it in his mouth, drop it by where u are, and lay on it. Or sometimes he'll *Give* it to you, like a present lol