Accepted wisdom is that cats sleep approximately fifteen hours a day. No wonder I have an affinity for them. Lazy day fantasies aside, I notice my girls indulge in three different kinds of sleep.
The first is a really deep sleep, when they're obviously out to it. In the curled up position, they often cover their eyes, and when woken, are clearly coming to consciousness. Just like us, they can be seen twitching and moving, as if dreaming...or at least there's something going on in there.
The second is what I call light snoozing, kind of like napping would be for us. Their body position is less protective, and can often be fully stretched out. Eyes closed, relaxed, slow breathing, they have the lot. But it takes less to wake them, and they're not as startled if I do wake them accidentally.
The third is almost not sleeping at all, more like a dozy wakefulness. Although they can be in almost any position for this, they're often in the cat-loaf mode, with all the legs tucked neatly away. If need be, they can spring to action quickly, if, for example, they smell food. It's almost like they're meditating. Who knows, perhaps they are.
Are yours the same?
Here are some more catnap facts.
Edit: And for good measure, a cat in deep sleep.