In addition to all the above points I also buy four boxes of baking soda, Canadian Tire often has the Arm and Hammer brand on for $1 each. I open the perforated sides and put one box in each footwell. Helps keep moisture and any odors down. Lastly I set six mouse traps and set them up at each end and midpoint of the garage by the walls. I dread the thought of mice getting into the wiring. Never caught a mouse yet!