Tonight my wife and I fell victim to what can only be described as a total aerial assault on our home, carried out by an angry mob of house flies. The combination of it being garbage pickup night, the temperature being higher than it has been all year, and our poorly installed air conditioners made us the softest target on the block. One fly in the house is annoying, over a dozen buzzing around feels like armageddon. The fact that I don't intentionally kill bugs just added insult to injury.
But in a bizarre twist of fate, my evening was saved by a junky little children's toy and a little bit of science.
I originally was chasing flies around the house crazily with this little vacuum gun and mostly just getting frustrated. Then, Jia had the smart idea to put the porch light on and kill all the other lights in the house, to try to trap the flies out on the porch. A smaller space made it easier to catch them, but still resulted in a mostly ridiculous game of fly and human in which the fly was impossible to catch until it landed nearby in sheer chance. After struggling for about 10 minutes, we were able to catch the two flies we trapped on the porch and release them outside. When I got back in the house, all the lights were off, and so I turned on the little red light on this cheap plastic gun that I always assumed was a shoddily built wannabe laser pointer. That's when the Eureka moment happened.
I could see a fly sitting completely still on the living room wall, and decided to try to sneak up on him, fully expecting him to fly away at the last moment. But for some reason, he didn't budge at all and I was able to catch him with ease. Before I had a chance to turn the lights back on in the room, I noticed another fly on the wall on the opposite side of the room, and repeated the process. Sure enough, I was able to walk right up to him and suck him up into the gun with ease. This is the exact moment where I realized that flies can't see well (or seemingly at all) in red light!
Within the same amount of time it took us to catch the first two flies, we hauled off 12 more by simply turning on a white light to attract them into the general area, then switching over to red light and sucking up two or three at a time. This was proof enough for me that the approach worked, but I wanted to verify it before writing about it so I'd appear at least slightly less insane. Sure enough, there is a fancy graph from a scientific paper that confirms my hypothesis.
That cliff you see on the right side of the graph is the red light spectrum, in which a fly starts to fail to see an approaching vacuum gun that is perched about 1cm from its face. Clearly, the manufacturer of this silly children's toy that saved me from a terrible night must have known that. It's sort of embarassing to admit that I didn't, but hopefully it made for an interesting story nonetheless.
While this informal experiment was conducted by accident due to my religious practices, I can only say one thing in summary that I might as well let XKCD say for me.
Hello, my name is Gregory Brown. I am the founder of Mendicant University, a free online school for software developers.
I am passionate about community service, education, and the free software movement. If you're interested in getting to know me a bit better, feel free to send me an email: gregory.t.brown@gmail.com
