It's a Cluster F-F-F-Fly on the Wall

Here's another thing that I discovered when I moved to an old farmhouse in rural Canada (why is it that other people discover gold or stock certificates in the walls): Cluster flies. So called because well, I don't really know. These things breed like no species I've ever encountered (I guess I should not say that - who knows what else I'll discover in the coming months).

There are so many in our attic that the floor has a half inch of dead ones at any given time (twice a year, when they hatch). They lay eggs in the walls - but now that we know what's up, those suckers are done for - I've got a plan. Cluster Busters. Fingers crossed.