I haven't seen any mice in or near my coop. I enclosed the run with 1/4 inch hardware cloth and that keeps even large bugs out. I do have a lot of chipmunks hanging out outside the coop & run lusting over the garden scraps and chicken feed. They don't stay too long as my hens lunge at them with such viciousness that is just a little disturbing. These are large, probably overfed Rhode Island Reds and they can be intimidating at times.