When I was young and living in my parents house, my sister, who had a private room in the semi-finished attic, kept hamsters. Her senior hamster escaped and was listed missing, presumed dead. The following Saturday, several days later, the family was in the living room on the first floor listening to the radio and we heard a scratching from the front door vestibule. It was persistent, so my father and I pulled the base board off and pulled a lath out of the way, and out stumbled the missing hamster. He had lost about a quarter of his body mass and was staggering, but immediately figured out the water bowl and food that was put in front of him. My sister had him around for some years after.