We are in a suburb that abuts farm land, there is a hay farm directly across the street from us, and every year when they harvest the field we get an influx of mice in our garage. We have (indoor only) cats so we never see any trace of them inside, but they like to try to find homes in our garage. Now when we see them ramping up to harvest, we start putting the cats in the garage at night and that pretty much handles it. I think just the smells of the cats keeps the mice from coming in; we don't usually find any "presents".
We did have some mice getting into our crawlspace for awhile; turns out they were crawling up the inside of our downspouts and getting in through the exterior. We had the access spot plugged and put screens over all the downspouts and that took care of that.
I won't put poison out because I have cats and dogs and I just don't trust them not to figure out a way to get at mouse poison even if it's "dog/cat proof". I don't like traps either...most of them are gross and/or cruel and I'm squeamish even about the humane ones. I prefer to just keep the beasties out in the first place if I possibly can.