I’m not too surprised that they’ve gotten into this habit. When I wake up most days, one or both of the cats are sleeping with me on my bed, which isn’t too unusual. I think pets see their owners as another animal, just like themselves, and most packs or groups of animals in the wild, sleep together. No. What I find most odd is that they always jump onto the bed on the exact same side, all the time. Linus always jumps on the right side of me and Lucy onto the left. That’s odd.