Does your cat like to sleep on top of you? The experts say it is a common feline behavior. Why do they sleep on us? It's probably a combination of factors. Cats love warmth. I have watched Inkee-Bear as he inches his body across a room to stay in the sun’s warm rays. So, maybe they sleep on us to keep warm. Cats sleep 15 hours per day. They are experts at finding the coziest spot to sleep. Sometimes that is on top of us.