How do i stop rats/mice from leaving droppings on my porch?

Question:I have a covered porch and they like to leave them in the corners.

Answers:
Fox urine. You can buy it (don't worry, it's an odorless-to-people powder) at the hardware store or a place like Lowe's. Sprinkle it around wherever you don't want most critters - cats, skunks, mice, etc. Works very well!