The traps that Katie mentioned seem to be your best bet. You should close all holes and (here I go, I am tired, I don't know the translation: gaten en spleten) where they can come through, and they can get through half a centimeter if they need to, so I heard. Put the traps close to the walls, because mice are agoraphobic, they HATE open spaces, they always stay near the walls. Also, they do NOT eat cheese, but they LOVE peanut butter, so if you get those traps that Katie mentioned, then put a piece of bread with peanut butter in it, they will flock to it...
Thanks Melissa! I didn't know they liked peanut butter.
You were correct about the high frequency devices too. As soon as I plugged one in, Cody squinted his eyes, shook his head and ran out of the room. I will keep them though and put them in a drawer. Chances are a friend may need to use one or two of them at their house.
Are they also agoraphobic in the dark? Last night when I turned on the kitchen light, one was scurrying across the kitchen floor very close to where I was standing. Maybe if I keep the lights turned on at night, they will stay hidden near the walls. I am going back up to the store to get some of those live traps Katie and Andrew told me about... and I will try your peanut butter suggestion Melissa!