Well, I looked around outside and found what I thought was the NEW entry point -- a gap under some trim. I filled it up with the foam insulation that turns hard. In all, we trapped/killed one mouse before I filled the gap and two after. Now, it's been a couple of weeks, the traps are empty every morning and I haven't seen any more of their little poops in the kitchen drawers.
How do I know when they're REALLY gone?