My cat Polap loved sleeping on the bed in the guestroom. She would head straight to the hollow between the two pillows, and sleep there. She'd leave her paw-indentations in the bed cover on the way, so I could always tell when she'd been sleeping there.
Poplap died about ten years ago. The guest bedroom hardly got used since, but my housekeeper Aletta keeps everything neat.
So Aletta is on holiday now, and a couple of weeks back, I went on the reptile-seeking excursion you know about. When I came back, I found the guestroom bed like that, with the little paw indentations heading straight to the hollow between the pillows, exactly as Poplap always made them!
Now ... could a different kitteh have gotten into the house to make them?
I do leave a couple of windows open at a crack. But you know me ... every single windowsill in the house is full of plants in small pots. I don't see how a kitteh could have gotten in without disturbing them at all. And there's never been one that was bold enough to enter the house. The neighbours have one that occasionally comes into the yard, and I saw another one a couple of times, but that's it. They're both fairly wild and easily spooked, I can't see any of them deciding to come into a strange house and have a nice sleep and knowing enough to find and make a beeline for the most comfortable sleeping place in here.
So... make of that what you will!