I do not know if anyone else is having this problem, but it seems I'm getting a bit problem with a stray dog / cat of the week. They always come at night and my sim wakes up. It goes downstairs to interact with it, till he reach the animal left. That is supposed to be homeless, technically. And to make everything worse, two of the cats had died on the porch of my house. The sims luck is horrible. Is there someone else has more luck with finding and befriending stray dogs / cats?