I have a basement smell I need some help finding and then eliminating. It smells like a dead mouse. The problem is that the smell only seems to occur when there is some air movement -- the dryer is on, the A/C, or people searching for the smell. The other problem is it has lasted for over a month. The smell accumulates under the curtained off stairs and on the staircase. I've used a flashlight, tried to sniff it out, and borrowed a beagle with no luck in finding the source of this smell. From what I've read it seems to be lingering longer than most mouse smells and I have never seen any mice or mice droppings. If it is in a wall I can't identify where it would be. Does anyone have any good methods of finding a smell especially one that occurs only with air movement?