They must know it was the rats; the slithering, scurrying rats whose scampering will never let me sleep; the daemon rats that race behind the padding in this room and beckon me down to greater horrors than I have ever known; the rats they can never hear; the rats, the rats in the walls...
When I first saw this thread, I instantly thought of The Rats in the Walls. Excellent reference, and very cool template; I'll probably end up using it in one of my campaigns sometime. Or, better yet, one of my PCs... I can see it now: half-elf bard in the walls. Hey, where's that eerie music coming from...