Daphne’s teeth were going to bounce out of her head if they didn’t shatter into little pieces first. The trilon car she was strapped into was decelerating from Mach 10. The trilons were built to accelerate from the ground, climb a smooth arc along the trestle to the platform, curve around the Earth at a few thousand kilometers per hour, and then gracefully descend down the other end, never exceeding 1.1g. They were not built to stop on top, 100 kilometers up. Hence the rattling and jarring as the maintenance car shuddered to a stop somewhere over Missouri.

Across from her, Fritz Pampil was smiling his big Haitian grin as if he’d done this a hundred times before.

“All out for the thermosphere,” he called. Daphne wanted to reach over and smack the grin off his face, but she was too busy trying not to vomit.

***

Three months earlier Assistant Professor Daphne Ernst had been grading freshman bio final exams for the UCI Class of 2068. She was worried she might not be around to greet the class of 2069 in the fall. First-year bio tended to sap time that would be better spent on tenure-worthy research. She should probably let the AI grade the exams, but she felt she owed the students at least one look at their work before failing them.

Daphne was up to question nine when someone knocked on her open door. “Office hours are Tuesdays and Thursdays, 3-6.” She looked up to glare at the student until he/she got the message; but instead of the undergraduate she expected, a gray-haired gentleman of sixty or so stood in her doorway wearing a suit more appropriate for a law firm than a college campus.

The man mistook her hesitance for permission and walked in. “I apologize for disturbing you, Professor, but I have a problem I was hoping you could help with.”

“And you are…?”

“Jim Rawshon, Trestle Edison.” He held out his hand. Daphne accepted it out of politeness, though she really didn’t have time for this. If she didn’t submit her grades before 5:00 PM, her inbox would overflow with anxious emails from 262 grade-grubbing premeds. The last time she was late with final grades, three students’ parents had called the dean.

Daphne put her tablet down. She might as well find out what he wanted. It had to be more interesting than undergraduate exams. “What does TE need with an entomologist? As far as I know, there aren’t any insects that make their home in the thermosphere.”

A look that might be surprise flickered across Rawshon’s face and then just as quickly disappeared. His next words were almost too measured. “Is that so? Definitely no bugs in the thermosphere? That’s…good to know.” He didn’t seem convinced.

“Some bees fly as high as 10 kilometers, and that’s still an order of magnitude lower than the trestles. Higher than that, there’s not enough air to sustain life, even insect life, much less allow flight. Not to mention the radiation problem. There are probably some protozoans and bacteria wafting around up there, though that’s not really my field, but nothing macroscopic.”

Rawshon shuffled nervously. “OK, so nothing can fly in the thin air. What about non-flying insects?”

“Non-flying insects? You mean carried on the wind or by a trestle?” Daphne paused to think. The trestle supported platform that transported freight between the world’s metropolises in a superconducting rail network and powered most of the planet with high altitude solar panels was 100 kilometers up, but spurs did connect it with the ground. If an insect had gotten up there, probably carried on the outside of a trilon, could it survive? No, the air would be too thin, even for a cold-blooded invertebrate.

Rawshon pulled a small plastic box out of his pocket. “I was hoping you might be able to ID something for us.” He handed her the box.

Oh God, just another amateur gardener with a bug he’d found in his rhododendrons. The curse of the academic entomologist. She glanced at it. Easy. She didn’t even need to pull out her hand lens. “Argentine ant. Linepithema humile.”

“Is it rare?”

“Anything but. There are millions of them on the UCI campus alone. It’s why our mascot is an anteater. The campus was built on top of a large Argentine ant colony.”

“Is there anything special about this ant?”

“It’s an incredibly invasive pest. There are trillions of them in California. They form supercolonies and displace many of the native ants.”

Rawshon looked puzzled. “Supercolonies?”

“Inside Argentina different colonies fight over resources and keep each other in check; but outside Argentina there’s really only one genetically identical colony. It’s just a very big one. Probably a single queen was transported to New Orleans sometime late in the 19th century. Since then, her descendants have spread out around the globe. Because they’re all related to each other, they don’t fight.”

Rawshon looked skeptical. “That’s it? Nothing that would make them especially resistant to cold or extreme environments or anything?”

“Excuse me, Mr. Rawshon; but I’m a very busy woman. I have grades due in two hours. Is there some reason you sought me out instead of the county agent? They’re better equipped to deal with these sorts of questions.”

Rawshon sighed. “Do you mind if I pull up a chair?”

She gestured at the chair in front of her desk, and he sat down.

“We found the ant I showed you on a trestle.”

“I’m not surprised. Like I said, they’re everywhere. Frankly, it would be a surprise if they weren’t inhabiting some of your stations.”

“Actually, we found it on top, a hundred kilometers up.”

“Still not surprising. It probably hitched a ride on the outside of a trilon. Entomologists are always finding dead insects far outside their natural range. Insects can be hit by a car, a train, or I suppose a trilon and be carried for hundreds of miles before they fall off.”

“No, you don’t understand. We found it alive.”

Daphne looked at the ceiling. Could an ant survive up there? Maybe. Insects survived freezing better than mammals. She routinely put insects in a refrigerator to slow them down for photographs. Once they warmed up they were as good as new. “Was it moving?”

“Yes, and so were the others.”

“There are more?”

“Lots more. We have video from the maintenance cameras.”

He made a few swipes on his tablet and handed it to her. The video showed a few black dots moving across a gray surface lit. Daphne couldn’t say conclusively that the dots weren’t ants. The footage wasn’t going to win an Oscar for best nature documentary anytime soon.

“At first we thought the moving specks were video artifacts and didn’t pay any attention. Then one of our engineers noticed that the artifacts correlated with power fluctuations we hadn’t been able to explain.”

Daphne zoned out while Rawshon explained how TE had found the ants. He seemed more enthused about the technical details of trestle operations than the much more interesting question of the ants themselves. Was there any way a colony could live 100 kilometers above the planet? At least one mosquito species had evolved to inhabit London subway tunnels. If any insect could do it, the Argentine ant was a good candidate. They were strong, voracious, and spread like wildfire when they didn’t get into a war with another colony. Still, 100 kilometers up on the trestles that now ringed the planet? What would they eat? More critically, what would they breathe? Insects didn’t need as much oxygen as mammals, but they needed some.

Daphne returned her attention to Rawshon who was blathering on about “superconducting fllamomogadgets” and “ceramic aerojellies.” But TE knew next to nothing about the ants themselves.

She called a halt to the discourse as Rawshon was launching into a detailed description of camera apertures and LED lighting. “Would you mind if I hold onto this specimen for a little while? I’d like to put it under a microscope.”

“Of course.” He beamed her his contact info. “If you find anything, we’d really like to know.”

***

Two days later, Daphne had her answer. The specimen Rawshon had brought her was clearly related to Linepithema humile, but it had evolved. In particular, the spiracles had grown fine hairs. She didn’t quite understand how, but she’d be willing to wager a doctoral student’s thesis that the hairs helped the ant absorb O2 more efficiently than the hairless spiracles of the earthbound parent species.

She’d tried to compare the biochemistry of the haemolymph from Rawshon’s specimen to haemolymph extracted from ants she’d collected in the garden outside Steinhaus Hall. Unfortunately, the single ant Rawshon had given her proved too desiccated to perform the test. A real comparison needed live specimens, and a lot of them.

She called up Rawshon’s icon on her screen and tapped it. She was expecting to leave a message with his avatar, but instead the real person popped right up.

“Professor, good to hear from you. Have you found out anything about the ants?”

“I was wrong about the specimen being Linepithema humile, though I still think that’s the parent species. The insect you brought me has some interesting mutations, including plumose setae in its spiracles that probably contribute to O2 absorption. The haemolymph also shows some intriguing hints of mutation that may explain how they breathe at that height.”

“We don’t really need to know how they’re alive so much as we need to know how to kill them. You’ve heard about the outage on the line between San Diego and Houston two months ago?”

“Of course.” 2,273 passengers had been stuck at the edge of outer space for sixteen hours until TE managed to jury-rig a rescue from a parallel line. The entire trestle network shut down for almost a week, disrupting transport and commerce around the globe.

“We think the ants caused it.”

“That seems unlikely. Even if an entire colony got in the way of a trilon, it would be flattened, like being hit by a windshield times a thousand.”

“They didn’t derail it. The ants ate through the insulation around one of the superconducting cables and shorted the system. Current bled into the platform so the cable couldn’t maintain a high enough field to push the trilons. The evaporated current fried a lot of the surrounding systems. That’s why it took us so long to get those passengers down.”

Linepithema humile did have omnivorous eating habits. “So you’re saying ants took out the trilon?”

“Yes, and that’s not the worst. Once we knew what to look for, we began finding ants on all the trestles. They’re an epidemic up there. We’ve had to shut off a third of the lines out of San Diego. We need to know how to kill them.”

“What have you tried?”

“We sent up some poison–”

“You got from where?”

“We hired an exterminator.”

Daphne snorted. “I’m not surprised that didn’t work. First, Argentine ants are really good at smelling poisons. They avoid most of them. Secondly, they’ve adapted to the commonly available baits that would incapacitate most other species. None of them work as effectively as they used to.”

“Are there less commonly available poisons?”

“A few things you might use in a house, if you didn’t mind getting cancer a few years down the road; but nothing that’s available in large enough quantities to decontaminate the whole trestle platform. What is it, 100,000 kilometers now?”

“That’s linear distance. The platform is five kilometers wide on top, so more like five hundred thousand square kilometers.”

“OK, way too big for any poison I know then, bait or sprayed. Let’s try a different tack. Have you done a census?”

“A census?”

“A team of entomologists samples the ant colonies in different locations. That would give us an initial estimate.”

“Doctor, you’ve ridden a trestle, right?”

“Yes, of course. Many times.”

“But never outside a trilon, I assume?”

“No.”

“Then you don’t understand what it’s like up there. It’s the border of outer space. There’s no atmosphere to speak of. You need a full pressure suit to breathe. The temperature is 200 °C at night, although the air’s so thin you’d freeze to death first. To top it off the solar cells are pushing currents through the planks that will fry anybody who steps in the wrong place.”

“And yet you think a colony of ants is living up there.”

Rawshon had the politeness to look embarrassed. “It sounds unbelievable, I admit, but you’ve seen the video. Now how do we get rid of them?”

Daphne stared at his face on her screen. “Mr. Rawshon, in the almost 200 years since Linepithema humile escaped Argentina, we haven’t been able to clear them from the UCI campus, much less eradicate an entire supercolony. I don’t know that you can get rid of them, and if you can I have no idea yet how to do it.

“The only thing I do know is that we don’t know anything: how they breathe, what they eat, how fast they reproduce, or where they’re living. If we answer some of those questions, then maybe I can figure out how to deal with your ant problem. But the only way to do that is to go up there and collect them.”

Rawshon frowned. “I was afraid you were going to say that.”

***

A trilon ride was one of the more boring experiences of modern life. You boarded the car in a ground station, walked down the aisle, strapped into a cramped seat, and then felt a slight acceleration. An hour or so later you got off. The biggest worry was whether you’d be seated next to a morbidly obese Midwesterner.

The maintenance car Daphne was trapped inside of was nothing like that. It was a repurposed freight container and looked it. A variety of robots, waldos, and machine tools whose purpose she could only guess at were strapped to various brackets and shelving. She was buckled into a hard plastic chair, utilitarian and not at all like the padded seats in the passenger cars.

Most critically, no lavatory was discretely located in the rear of the car; not that it would help if there were since she wouldn’t be able to use it without removing her airtight space suit, and she couldn’t do that without at least two other people to assist. The trip out, trestle walk, and return journey were only supposed to take three hours, but if something went wrong and she was stuck up there (as had happened on the Mexico City trestle the previous week, an incident that had finally convinced TE to risk sending her up top) she was peeing in the suit. She’d skipped coffee that morning as a precaution, and now that the nausea had passed along with the remains of her breakfast, she was feeling the first tingles of an oncoming caffeine headache. If she survived this, she promised herself she’d never tell another trilon joke again.

Fritz unbuckled himself, then began to unstrap Daphne from her harness. “You OK?” he asked.

She gave him the thumbs up sign even though she felt like she’d gone three rounds with the women’s heavyweight champion. She stood and flexed her arms. The bulky suit made moving cumbersome, but no more so than it was on the ground.

Fritz muttered something into his suit microphone, then nodded and turned to her. “Ground has switched the current out of this track. It’s safe to go for a walk now. Remember, once we break the seal, we’ll be in vacuum until we get back to ground.”

Daphne nodded. Human maintenance was rare enough (and the trilons fast enough) that it was cheaper to evacuate the car than pressurize it. That was why they’d come up in a refitted freight container. Passenger cars were airtight, but weren’t meant to open at less than an atmosphere.

Daphne began attaching tools to her suit. An aspirator wouldn’t work in the near vacuum, and she couldn’t suck on one through the helmet anyway. Assuming the ants couldn’t bite through her suit, a sting stick wouldn’t be necessary. Otherwise she’d brought her usual kit: a small macro camera for documentation and magnification, a couple of fiber optic lenses to explore any colonies they found, forceps to collect specimens and plastic tubes to hold them, a small brush to sweep ants into the tubes, and a trowel to dig with. Fritz had teased her about the trowel–”What do you need that for? Digging up the floor?”–but she insisted. Sometimes the simplest tools were the best.

Fritz cranked the large handle by the door which retreated into the wall. Even through the helmet, Daphne could hear a hiss as the air escaped.

Outside, the platform looked smooth and almost icy in the LED light from her helmet lamp; but Daphne’s boots gripped it well enough. It didn’t feel much different from walking on a sidewalk on campus. If she fell, nothing more than her pride would be hurt. They were over a kilometer away from the edge. Other than the lack of walls, she could have been looking at the floor of her laboratory back at the university. A less hospitable environment for Formicidae she could not imagine.

Fritz’s voice came through her ear plug. “Turn off your suit light and look up.”

Strange. She switched the light off. Then she looked up and gasped. The black sky was awash with thousands, no millions, of tiny points of bright light. Part of the sky was so full of stars it was almost a ribbon of white light.

“Impressive, isn’t it?” Fritz said.

“I’ve heard about this, seen pictures of course, but I had no idea it was so…so beautiful.”

“Haven’t been able to see stars like that from the ground since before we were born. Hard to believe everyone on Earth used to be able to look up in the night sky and see that. We might get that back in another few decades, if we can keep the trestles pumping the solar energy down to ground.”

Daphne wanted to stand there looking at the stars, but their time was limited and she was here for entomology, not astronomy. If she couldn’t figure out how to control the ants, the world would resume burning things for energy, with all the damage that entailed, and no one would ever see the stars from the ground again. She forced herself to look down, away from the celestial tableau.

The trilon they’d rode in was the only obvious break in symmetry so she used it as her starting point as she turned and took stock of the surroundings. The trilon itself was a large equilateral triangle. The base recessed into the floor of the platform along the path. The car, a big rectangular box exactly the size of a freight container, hung from a carbon rod attached to the top.

A line of solar panels ran parallel to the track on each side. Each panel was as tall and wide as the university library and sat on top of a large column that enabled it to track the sun. A couple of hundred meters past that another line of solar panels receded to the horizon, and then another. The pattern repeated on the opposite side. The scale made her feel like an ant herself. Awe inspiring as the platform was, it was also the most symmetrical and barren environment she’d ever seen, like a desert in the sky. Of course, as every field biologist knew, deserts were full of life, if you knew where to look.

Now where were the ants? A popular urban legend said there was nowhere on earth you could go where you’d be more than one meter away from a spider. The claim was more likely to be true of an omnivore like an ant than a top predator like a spider, but it wasn’t that true. How could an ant, much less a colony of them, live up here?

“So where are these ants you’re so excited about?”

“They’re up here. Just look for movement.” The helmet radio made it sound like Fritz was talking in her ear. “Wait, there’s one.”

Daphne turned toward where Fritz was pointing as fast as she could in the bulky suit, but whatever he’d seen was gone.

“Don’t worry,” he said. “There’ll be more. Here comes another one.”

This time Daphne saw it. A single worker hurrying across the surface. She tried to intercept it, but in the cumbersome suit she was slower than it was. No matter. Where there was one ant, there would be more.

Thirty minutes later she still hadn’t seen a third ant and was beginning to doubt her initial sighting. “I don’t get it. I thought you said they were all over the place up here.”

“They are. Or at least they were. We picked this spot because it’s one of the places the cameras have detected the most movement, and we’ve seen the most fluctuations in the power.”

“Then why am I not seeing any?”

“Don’t ask me. You’re the ant girl. I’m just an engineer.”

Ant woman, Daphne almost corrected him, but she bit her tongue. She couldn’t afford to piss off her ride home, not when the nearest station was a kilometer south and a hundred kilometers down. Still he was right. She was the ant woman. How would she treat the problem if she were in the jungle and trying to locate a hard-to-find species? First she’d put out traps. The robots had done that, but they’d only brought back a few workers. She wanted a queen, which meant she had to find a hive.

Anywhere else she’d check bushes and plants, especially flowering ones. Of course there weren’t any bushes up here, much less flowers. The only things that extended above the platform were the trilon they’d ridden in on and the solar panels. Was it possible the ants were using the solar panels as some kind of bush, or food source even? She didn’t see how, but it was worth checking out.

Forty minutes later Daphne was sitting at the base of the third panel they’d inspected. Not a single ant. She was beginning to wonder if this was all some elaborate practical joke. A ridiculously paranoid thought, of course. No one would spend the sort of money and effort it took to get her up here on a joke; but damn it, there should be ants.

Daphne looked out at the landscape, gray and cold. In fact, it only looked cold. It was actually quite hot. Did that explain anything? Were the ants somehow collecting energy from the solar radiation? No, of course not. They were insects, not plants. She felt like she was forgetting something. What had she been doing before she and Fritz started trekking down the line of solar panels? Oh right, she’d been asking herself how she’d go about looking for a mystery ant in the jungle. She’d set out traps, she’d check the bushes, she’d dig into the leaf litter (none of that here), she’d set off an insecticide bomb to bring down any ants in the canopy, and she’d dig into the ground to see if the ants were moving beneath the surface. Hard to see how any of that applied here. Maybe the tops of the panels were a canopy? Could the ants be living on, or in, the panels? “Have you had any problems with the solar panels?” she asked.

“No, just the cables that transmit the current.”

“But the panels feed into the cables, right? Ants in the panels might travel along the cables.”

“It would be Kentucky fried ant, if they did. A lot of current flows through those wires.”

Daphne looked up at the top of the panel she was sitting under. “Any way we can get up there?”

“On top of the panel? I don’t think so, but we could have a robot bring one down for you.”

“OK, if we don’t find the ants, we’ll do that.” In the meantime, where were the damned ants? If this were an urban park, she’d wave her hand around in the grass, dig a hole or two in the dirt, or turn over a dead log; and, more times than not, an ant would go scurrying by. Absent-mindedly she scratched at the surface with her glove.

“Careful,” said Fritz. “You don’t want to damage the floor.”

“Wait, what?” said Daphne. “How I could damage the floor?”

“It only looks like stone. It’s not that tough.”

“But it holds up all these panels and trilons?”

“And a steel ship still floats. It’s how the load is distributed, not how dense the material is. The aerogel planks are friable. The dendritic microstructure gives them an exceptionally high compressive strength, but a very low tensile strength.”

Daphne understood approximately none of that. “Fryable? You mean you can cook it?”

Fritz laughed. “Quite the opposite. Friable with an i, not fryable with a y. It means it shatters if you press too hard. It will hold a huge load. Just don’t hit it with a hammer. You went over this in training.”

“I must have been out sick that day.” Or asleep. Some of TE’s instructors could have out-monotoned the worst emeritus in her department. But that didn’t matter right now. If she could damage the floor with her gloved hand, could an ant’s jaws cut it? She detached the trowel from her suit. “I’m going to dig.”

“I’m not sure that’s a good idea. You might hit a power line.”

“You told me the power was cut off in this plank for now.”

“Yes, but–”

“No buts. What happens if I break it?”

“We’ll have to send the waldos out to fix it. They extrude more gel, the same process used to build the trestles, only on a smaller scale.”

“If I dig, will we fall through?”

“Not for a few meters at least, but I don’t think you ought to do that.”

Daphne sighed. “We’ve been up here for two hours now. So far I’ve seen a grand total of one ant. I’m betting they’re living inside the floor.”

“I suppose it would explain why the waldos couldn’t find them,” Fritz said but he didn’t sound convinced.

“OK, then,” Daphne said. She positioned the point of the trowel on the floor and shoved it in. She tried to scoop out a piece of floor, but instead it shattered and fell apart like a Christmas tree ornament, only without the parent-alerting tinkle.

Fritz said something in French, but Daphne didn’t hear him. She was too distracted by the wave of small brown ants pouring out of the hole. She couldn’t see as well through the helmet as she could with the naked eye, but she could still make out workers, drones, and pupae. Some of the workers were frantically trying to move the pupae. She didn’t see a queen, but there had to be one in there somewhere.

She grabbed the brush from her suit and reached behind her. “Give me a plastic bag. I think we found what we’re looking for.”

Fritz handed her the bag, and she started whisking as many of the still swarming ants into it as she could. She collected about 30 before the rest of the ants escaped. It wasn’t as efficient as an aspirator gun, but it was a good start.

When the swarm had dispersed, Daphne looked into the hole. It was about a quarter meter in diameter, and maybe half that deep in the center. The bottom was covered with what looked like small shards of glass and ant corpses in about equal numbers. Had her incursion killed them by exposing them to the near vacuum? That seemed unlikely. They could survive at least brief exposure to the surface. Her gloved fingers were too awkward to pick up an ant, so instead she picked up a shard of the broken floor and used that to scoop up an ant and hold it up to her eyes. She couldn’t see too clearly through the helmet, but it looked like it had been dead a while. She strapped the brush back on her suit and unhooked the camera. Under magnification, she could see the head was missing, and an extra leg was growing out of the ant’s back.

She scooped up several more dead ants. Most of them were just body parts, but the pieces didn’t look right. Legs were missing. Antennae were misplaced. The thoraxes were too thick or too thin. She’d have to put the pieces under a microscope to be sure, but somehow she didn’t think these were casualties of intercolony warfare.

***

The last of the TE bigwigs strolled into the conference room and seated himself at the back of the table, opposite Daphne. He was wearing a Patek Philippe monocle display that probably cost somewhere north of her annual salary. That made seventeen present locally and twenty-two others dialed in on VC. Not quite freshman bio numbers, but a big enough audience and much better dressed. On the other hand, unlike her university students, she couldn’t force them all to turn off their Internet glasses and pay attention.

The admin who was taking notes closed the door. “Dr. Ernst, if you’re ready?” He smiled at her. At least she had one friend in the room.

Daphne touched a button on her tablet. A high resolution picture of the new species, tentatively named Linepithema altum, flashed on the screen in the front of the room.

“Mother of God,” someone swore.

Daphne smiled. “Don’t worry. That picture is several thousand times larger than life. The ant you’re looking at is smaller than the nail on your pinky finger; but yes, that is the monster that’s eating your trestles; and there are millions of them; maybe billions. If they aren’t controlled, there’ll be trillions within a few years.”

Daphne flipped a slide. “For comparison, this is the Argentine ant, the parent species from which the trestle ants evolved.”

An Indian woman in a lavender pantsuit stuck up her hand. “I thought evolution didn’t work that fast?”

At least one person in the audience remembered her high school biology. Daphne had to be careful. This was by far the weakest point of her theory. “Normally it doesn’t; but these ants breed very quickly, and radiation in the thermosphere increases the rate of mutation.”

She flipped the slide again to show the pile of dead ants she and Fritz had uncovered. “These are some of the mutations that didn’t make it. The ants aren’t just breeding faster. They’re evolving faster. That’s one reason poisons and bio agents are unlikely to work. With this rate of mutation, they can adapt to anything we throw at them faster than we can apply the pesticides.”

The woman in the lavender suit looked satisfied with the answer. Good. Daphne had three grad students and seven AIs working on the problem, but she still couldn’t conclusively say why or how the ants had evolved so far so fast.

The man in the back of the room with the expensive monocle – Daphne thought he might be the CEO – pointed at her. “I’m sure this is interesting, Professor, but all we really need to know is how to get rid of them.”

“I’m afraid you can’t,” Daphne replied.

“I’m sorry,” he said. “I thought we were here because you had a solution.”

“I do have a solution, but you can’t get rid of the ants. They’re established now.”

“So what do we do then?”

“There’s only one place with the right climate where Argentine ants aren’t a problem. Any idea where?”

The man glowered at her. Maybe now wasn’t the best time for the Socratic method. She flipped the slide to reveal a world map and pointed at the southeast side of South America. “Argentina.”

“Then why are they called Argentine ants?”

“Because that’s where they come from. Only the ants there are different.”

“Different how?”

“In Argentina, the ants don’t form two or three supercolonies like they do in the rest of the world. In Argentina, thousands of genetically diverse colonies compete with each other. Everywhere else, it’s like the ants recognize other ants as cousins and won’t kill them. In Argentina though, where there are different colonies, they keep each other in check.”

“How does that help us? We can’t run all the trestles through Argentina.”

“Your problem isn’t that you’ve got ants on the trestles, or rather inside the trestles.” She flipped the slide to show a video of the ants scrambling after she’d broken through the floor. “The problem is you only have only one kind of ant. You need more ants. Establish colonies with diverse genetics and they won’t smell right to each other. They’ll attack each other and keep the population in check.”

“You want us to put more ants up there? Isn’t that what got us in trouble in the first place?”

“No, adding ants wouldn’t work. Regular Argentine ants wouldn’t survive in the thermosphere. You need these new mutated ants.”

“Excuse me, Professor, I’m sure this is an interesting story for a college seminar, but we need practical solutions. The amp meters show the problem is getting worse. If we don’t fix it, most of the trestle network will be out of commission in a year.”

Daphne smiled. Good, they were desperate. She’d been worried they weren’t going to like her proposal. She flipped the slide.

***

Daphne looked through the microscope at the latest specimen TE had sent her. She had promised to name this one after her niece, Linepithema altum anneliese. It was the 813th new subspecies collected this year, though they were getting harder to find. The radiation on the trestles was high enough to kill most species. Only a fast breeding insect like Linepithema altum could survive the unshielded mutation rate up there.

In the wild the parent species, Linepithema humile, didn’t mutate much at all. As soon as an ant mutated far enough to smell different to other ants, they attacked and killed it. The initial mutant queen who had founded the supercolony on the trestle could only have done it because there were no other ants up there, much like the initial queen who had founded the Californian supercolony.

The trick had been to deliberately separate the supercolony, and the only way to do that had been to cut gaps in the platform every kilometer. The cost had been staggering, not as staggering as the initial construction of the network, but ruinous nonetheless. TE wouldn’t show a profit for at least a decade; but faced with the prospect of losing the trestles to the ants completely, they had buckled down and paid.

Once the ants were separated, speciation was guaranteed, given the high mutation rate at the border of space. When the planks were reconnected, the newly divergent ant colonies promptly went to war, and reduced their numbers down to a level that was no longer a threat to the trestles. The ones that were left still nibbled at the wiring, but the damage was slow enough that the robots could keep up with it.

She smiled. The tenure those papers had earned her was well deserved. Best of all, she didn’t have to teach freshman bio anymore.

A knock on the door interrupted her reverie. She looked up to find a dark complexioned woman – maybe African? – dressed in a Louis Vuitton sari Daphne could neither afford nor pull off.

“Excuse me, Professor. I understand you have some experience with insect infestations in industrial situations. I have a fly I was hoping you might take a look at.”

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About the Author

Eliotte Rusty Harold is originally from New Orleans to which he returns periodically in search of a decent bowl of gumbo. However, he currently resides in the Prospect Heights neighborhood of Brooklyn with his wife Beth and dog Thor. His short fiction has appeared in Alfred Hitchcock’s Mystery Magazine, T. Gene Davis’s Speculative Blog, and numerous anthologies including The Time It Happened, Only Disconnect, Abbreviated Epics, and Master Minds. When he’s not writing, he enjoys taking macro photographs of ants, Argentine and otherwise.