I completely agree! I work near the city and we just had a cold snap where things were going below freezing. After not seeing any mice in years THREE of them came into our work building. We actually caught them and let them go again outside. I think they are cute, but I don't want them scurrying around my feet. The fact is that animals will try to find warmth when it's cold. I would too!
Same goes for spider-season where they like to come inside (I lost a star from a review because they saw a spider).
In the summer of 2015 an extended family were guests and they complained that when they were entering the house a mouse tried to get in (inferring that they wanted to be compensated). I simply wrote back that I certainly hope they didn't let it in! Really?! A mouse tried to get in? You're in the mountains with lots of critters running around. Like @cabinhost we also have bears (and coyotes and cougars) in the area... be glad it's not one of them in the house.
I leave out poison only in areas that I know cannot be accessed by guests. I have purchased the high-pitched squealers and put them around the house. Apparently only animals and young children are bothered by them so I put them away when there are children staying. There is only so much you can do to rid your house of them - sometimes it's going to happen.
Did you know that sprinkling whole cloves around an area will keep mice away. Of course, you don't want your guests stepping on cloves, but you can put them in areas that are out of the way.
Another great tip for ants: put fabric softener sheets around the areas you see them, including the line that they like to follow and you won't see any more ants. I did that last spring and never saw another ant again!