So my friend Aimee (Newrotic Girl), the self-proclaimed mouse guru, said to gently discourage the mousies I should take "cotton balls and put 1-2 drops of peppermint essential oil on them." When she did it, she "Tucked them into the corners of my living room, bathroom, and kitchen (it wasn't a large apartment). You might want to put them in places where there might be a hole in the wall -- like where hoses come in for washer/dryer or heat or stove or whatnot." Simple enough. I ran right out and bought the essential oil.
This evening I went through the apartment stuffing little cotton bits here and there. I might have over done it. It smells like the Doublemint Chewing Gum International Chewathon is taking place here. I now know how this little remedy works: it burns the crap out of their little mousy noses cuz I know my sinuses are clear.