This feels like déjà vu. Almost one year ago we had the same problem. This time we just can't figure out where they are coming in from. We have been having issues in the garage and the back yard with both mice and rats, but none inside till now. Luckily we caught them day one, so there isn't much damage... yet.
I am including these for our personal history. Feel free to not look at them, it's gross.
There are lots more, but you get the picture...
Anyways, I was really upset at first but now am more calm. We got rid of them last time, so it should work again. My question for you all is, have you ever had rats or mice in your rental homes and would you continue to live there is it was a repeat problem? What does it take for you to say, "that's it we are outta here?"