We have some sort of critter in the wall between my computer room and the living room. My guess is that it is either a mouse or some sort of bug that got in the wall.
Laurie crawled down under the house yesterday, but she couldn't find any sign of mice in that area from underneath, so in the next day or so we will try from up in the attic.
I'm not really a fan of anything that kills mice and leaves them to rot and stink where I cannot easily reach them, and our attic ain't that easy to reach.
What I think I'll try first is a solution that many people on the web seem to swear by, peppermint oil dripped on cotton balls. It seems that rodents are supposed to be allergic to peppermint and spearmint. I'm sort of wondering if it is in fact any mint, since we have quite an excess of catnip around that I could quite easily sprinkle up in the attic.