Opened camper today for the first time. Fixing roof seal,I could smell the tell take sign of mice,the strong scent of urine! Opened it up, and found a nest on front bunk. Good thing it was on top of an old mattress topper. Threw that away,and vacuumed off mouse droppings from the mattress that came with camper. Didn't look soiled or eaten,so washed that,and now drying on deck railing. Foam we just sprayed with a pet urine deodorizer. Hoping that works. Good news is that the mattress topper,was too small for bunk. Was from previous camper,and we wanted to replace it anyways. Now I have the excuse to go shopping for another! Found that I left a roll of toilet paper in shower enclosure, and that was the building material for the mouse condo.