I killed the rats in my basement ceiling. At the time, they were my biggest problem.

Then I found myself in my car one night with the headlights aimed at my back door, hoping to lure a swarm of carrion flies out of the house. Carrion flies, if you’re not familiar, are the kind that lay their eggs on dead things. So then that was my biggest problem.

It all started with a gnawing sound in my basement, in the ceiling above the family room. The steady crunch-crunch of rat teeth on rafters didn’t bother me much at first; I just turned up the volume on the TV. But then the entire basement began to smell of rat urine, which turns out to smell a lot like people urine. Eventually, it didn’t matter how much Febreze I sprayed; we had hit, as I called it, RATCON 5.

My next step was to push little green blocks of rat poison into the ceiling space behind the recessed lights. This turned out to be a mistake. Not only is rat poison bad for the environment and wildlife, but this tactic also left the sated rats free to scurry into some far corner of the ceiling space to die. An exterminator poked around up there, and shrugged. “Can’t find ’em.” Soon, my basement took on a new odor: eau de dead rat.

For the next week, I slept with my windows wide open for fresh air, and the flimsy lock on my bedroom door set against possible intruders.

But the gnawing stopped. And I celebrated my hard-won victory. I had toughed out the stink, and the worst was past. I thought.

Two weeks later, I came home from a trip and opened the door to Flymageddon.

The house was filled with giant flies. I realized instantly that the dead rats had become a breeding ground for blowflies. Blowflies are described by Wikipedia as medium to large flies, but I would describe them more as flying bookends.

Dozens buzzed around the kitchen, thunking into me as I made my way in. I needed a weapon, and I needed one fast. Years ago, Uncle Rocky and Aunt Martha, who live in Abilene, gave me a gag gift in the form of a giant three-foot, turquoise Texas-Size Fly Swatter. Turns out, it was the best gift ever.

So there I was. I gripped the Texas Fly Swatter like a baseball bat and slowly opened the basement door. I could hear the hum. My pulse was pounding.

View Images Bluebottle fly. Ripanvc Kinda pretty, actually. The bluebottle fly.

I flipped on the light and saw thousands of big dark flies, each the size of a dime, peppering the walls and window shades. Flies filled the air, and bumped against the ceiling with little buzzing thuds. Suddenly a squadron broke ranks and rushed straight up the basement stairs at me.

Or at least it seemed like they were flying toward me. I was watching a black wave of flies boil out of a light fixture in the ceiling, so I was a little distracted. But I’m pretty sure I made a noise like a creaky hinge, and slammed the door shut.

Now what? No way was I opening that door again without chemical weapons.

So armed with a can of Raid, I cracked open the basement door, stuck my arm in and sprayed a long satisfying ssssssssssssss. Yessssssssssss, I thought as I sprayed.

Now normally, I’m the live-and-let-live, shoo-em-out the door kind of person. So I also tried opening the kitchen door and stirred up a cluster of flies to usher them out. In return, they promptly flew straight for my head. All bets were off.

I needed a plan—and a partner. I was home alone, but that didn’t stop me from dragging my husband Jay into the scene from 500 miles away. I called him on speakerphone blubbering about flies.

The great thing about being married is that you can take turns being brave, and when one of you is freaking out and ready to burn your house down, the other one can spring into action. And even from 500 miles away, Jay sprung. “Go downstairs and open all the windows to let them out,” he instructed. I politely declined. As in, “What?! NO NO NO NO! Not until some of them are dead. Or most of them.”

Jay thought.

“OK,” he said, “Turn off all the lights in the house, and go turn on the car’s headlights. In fact, put the brights on. Then, open the basement door.” Flies, of course, are drawn to light. It’s not entirely clear why some insects fly toward light, but it’s probably why you’ll find flies clustered on windows. (At least at my house you will.)

View Images One of the fallen in my battle with the flies. Erika Engelhaupt One of the fallen in my battle with the flies.

It sounded like a plan that might work. So I carefully unlocked the basement door from outside; a couple dozen flies hovered between the glass and the window shade. I pushed the door open and ran for the safety of the car.

“Don’t fall and hurt yourself running from flies!” Jay yelled, still on speakerphone. “They can’t hurt you.” At this point, he’s picturing me laid up with a broken leg, a victim of my own horror of animals that don’t even have mouths that can bite.

“I know that, logically,” I said. But when it comes to a swarm, it’s not about logic. Since I write a blog called Gory Details, you might think it should be hard to turn my stomach, but it’s not. There’s a psychology test for how easily disgusted a person is, and I turn out to be entirely average.

So this is how I found myself in my car at 10:30 p.m., watching flies meander out the door and trying to decide how long I could run the brights before the battery died.

On cue, my mother called. Hoping to help, she looked up flies in the encyclopedia and reported that the pupal stage lasts two weeks. (My mother does not use the Internet much.) Her book didn’t say how long the adults live. “Hm, well, anyway, they’ll die eventually,” she said, “if you wait long enough.”

And I waited. The flies have kept coming. Every morning now, I vacuum up the night’s casualties, and every evening I come home to more. The other day, I arrived at work and dropped my purse on my desk, and a fly flew out. To cope, the Texas Fly Swatter and I have created a no-fly zone in my bedroom.

In the meantime, I have learned a few things about my opponents. I have three kinds; one is big with a shiny blue backside and another small and the prettiest green up close. The big blue ones might be the bluebottle fly Calliphora vomitoria—appropriately named—or Calliphora vicina, the urban bluebottle fly. The little green guys are probably a species of Lucilia, the nice entomologists at bugguide.net told me after I posted photos.

As those petered out, the biggest flies emerged—flesh flies of the genus Sarcophaga. Like sarcophagus. They’re enormous, and they buzz when they fly, and they are still in my house.

View Images My little Lucilia. Erika Engelhaupt

All three have their charms. Lucilia maggots have an amazing ability to eat dead flesh and ignore the living, so they’re used in maggot therapy to eat away dead, infected tissue. This works fantastically, but of course assumes that you can talk someone with, say, an oozing foot ulcer into letting a mass of maggots eat away at their foot—I suppose you say to the person that they’re only going to eat your dead foot.

I thought talking to a forensic entomologist might help me appreciate my new housemates. Sibyl Bucheli studies insects at Sam Houston State University (home to a great criminal justice program) in Huntsville, Texas (home to the busiest execution chamber in the United States). I knew I’d like her when her email arrived with a photo of her wearing a Wonder Woman tiara. (You should also check out her entomology lab’s Harlem Shake video.)

Bucheli told me about the first recorded case of forensic entomology in the 1300s. It involved carrion flies—maybe one of the species zipping around my head as I talked to her. The Chinese lawyer Sung Tzu was investigating a stabbing in a rice field and had all the workers lay out their sickles. Blowflies immediately landed on just one, even though it had been wiped clean, and Sung Tzu knew that the sickle bore traces of blood.

One of Bucheli’s students tested this method, she tells me—and found that blowflies can indeed find a bloodied and wiped-clean surface within minutes, or even seconds.

As for my flies, Bucheli says I’m probably on the second generation by now, at least. The flies have been multiplying, babies growing up and having babies of their own. I suppose it would be sweet, if the family home being handed down wasn’t a dead rat.

What’s more, she gives me bad news about the yellow-orange spots all over my windows. “That’s fly poop,” she says. “Sorry. They’re pooping on your curtains.”

Still, she made me feel a little better about them. For one thing, she’s totally brave about flies, and it made me want to be just like her. Bucheli has been at actual crime scenes, with dead bodies covered in flies. Even then, they don’t bother her. “I feel calm if I’m in a place with a million flies,” she said. “But if I’m in a city with a million people around me, that freaks me out… I understand the flies.”

They’re just being flies—eating, mating, pooping, laying eggs. They aren’t out to get me, or anyone else. “The whole six-legs, four-wings thing is beauty to me,” Bucheli said.

I’m trying to get there. In fact, I only used the Texas Fly Swatter once this morning.

But last night, after I cleared the sofa of dead flies and settled in for an episode of Bones, I heard it. The crunch-crunch of rat teeth on rafters.

This time, it’s war.