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The houseflies of my Chicago youth flew around at random. Here, I have flies that congregate in the exact center of the room, never land, and fly in straight lines with sharp right-angle turns. What's the point?
—Fly Girl
It was years before I lived in* a house clean enough to make that cloud of flies need an explanation. Until recently, I assumed it was just another product of my appalling housekeeping, like the possums under the sink and the dead priest in the fridge.
In the same way that Portland houses aren't insulated "because it doesn't get that cold here" (meaning you can freeze when the outside temperature is 50 degrees), Portland windows don't have screens "because we don't have that many bugs here."
Which, of course, means that all the bugs we do have are partying in your living room. And "partying" isn't a figure of speech—not to gross you out, Girl, but that cloud of flies in your parlor is basically a down-and-dirty singles bar.
"Being small, insects have challenges in terms of finding others of their species to mate with," says Joshua Vlach, an entomologist with the Oregon Department of Agriculture. In short, they need a mutually agreed-upon place to go to get laid, and for the lesser European housefly, that place is the center of any shady, enclosed space.
The cloud you're seeing is a bunch of dude flies trying to establish aerial turf over each other, the better to mack on any blacked-out lady flies who might drop by. The "right-angle turns" are actually two fly bros coming together in a tiny, split-second shoving match. (If you slow down a recording of their buzzing, you can actually hear them saying, "Not cool, brah.")
"The bigger the group of swarming males," Vlach says, "the more attractive it is to females." What's so appealing about a seething mass of belligerent, horny males—either in your living room, or at the Jackknife bar? I guess some mysteries transcend the bounds of species.
*Technically, "broke into."
Willamette Week