Do Cats Lay On Their Back With Tung Out. When a cat stretches out and shows their stomachs, they are. Sleeping on you, sleeping under the covers, and laying on their backs.
Most of the time a cat that is on its back is comfortable and happy. If you are allowing your cat outside by building a cat flap into your door, it will most certainly be used for a daily hunt. Cats will lie on their backs when they're happy.