Last year I thought that a rat may be in my RV then found that instead of rats it was squirrels. I had found droppings in the RV so I googled animal poop and found a website where you compared poop pictures to identify what the animal was. Who would have known that there is a web sited dedicated to poop (and not be a politician). I sealed every opening I could find with steel wool and sprinkled animal repellant around the site. I also put poison in the basement and got the offender. I have not had a problem since.