2yrs ago had a mouse problem. Went the local janitorial supply and got 5 urinal tabs. Most guys recognize the big non edible peppermints. Didn't unwrap them-- just placed them randomly. Haven't seen any mice since.
The original problem was using rat poison, it dehydrates the pest so they go for water, one went for my black tank and actually ate a hole in it, but the tank repair is another story!