A cat might be squatting like a hen because it's cold. This posture allows the cat to curl up more, reducing the exposed surface area of its body and thus minimizing heat loss. If you notice your cat adopting this "hen squat" posture in a cold environment, it's probably trying to keep warm.

Another point is that cats usually use various methods to mark their territory. When a cat feels threatened or unsafe, it will choose a "hen crouch" posture to hide itself and avoid being discovered by other animals.