 Would it be because a cat hears a heartbeat or some type of breathing? I just don't know the reason how they know. It really was documented. I read about it a long time ago. Oh, no, absolutely. And they have the purring. They have the ability to hear so much. And I think that's why they're so helpful in healing people themselves. They sense when something's going on and they come right up to you and use their purring power.