Bugged Read online

  In terms of total population, there are about 10,000 trillion of our notorious picnic invaders. Dorylus wilverthi, aka African driver ants, exceed the largest of superorganisms known in the world. Each colony holds around 22 million ants (as heavy as a giant Thanksgiving turkey). Over a 250-year course, ants aerate enough topsoil as to add one inch to the world’s surface. One colony alone in Brazil—a country where social termites and ants compose two-thirds of the biomass—moved 44 tons of soil. (Comparatively, African termite colonies can aerate over 1,000 tons of subsoil per acre.) One supercolony of Formica yessensis, covering 675 acres, with over 1 million queens at work, was recorded in 1979 on the Ishikari coast in Japan’s Hokkaido Prefecture. Argentine ant colonies in foreign soil can cordially work in proximity to one another, functioning as a sole “unicolony” that can span an entire state. Hence why some entomologists began aptly referring to these ants in the 1990s as “the Genghis Khan of the ant world.” Some more food for thought: rock ants measure the dimensions of a potential new home to confirm its suitability; driver ants create guard walls for food passages; fire ants float atop Brazilian rivers interlocked as a “life raft,” reproducing until they find a safe port to recolonize; wood ant colonies can haul up to 100,000 caterpillars a day; honey pot ants sometimes gather a posse of merry (wo)men and pounce on and rob nectar-wealthy ants; and weaver ants use their larvae like construction tools, manipulating them to produce silk to tie2 the leaves of their nest together.

  This advanced level of cooperative organization in animals is known as eusociality. It is found in ants, termites, wasps, and bees. I’ll focus only on the former two here and save the buzzy creatures for later. Such sociability encourages political and ideological parallels to humanity. Touring any human city makes the analogies apparent.

  One day in Houston, for example, I saw men in hard hats demolish pavement to replace sewer pipes; police cruisers surveil streets as businesspeople scurry about; diners at a restaurant eat locavore meals on a sunny patio; three men individually approach a woman at a bar; and overlooking it all from high-rise windows, a CEO watches the silent footsteps of workers as they toil below.

  Similarly, beneath an anthill in nearby Jessie H. Jones Park, worker ants mine dirt to build windy corridors in an effort to expand their colony’s reach; patrol soldiers surveil tunnels, guarding workers from pests; ants slurp fungus farmed from locally foraged decaying leaves in a dark bulbous chamber; three winged males inseminate a flowery, virgin queen outside the anthill (afterward, she’ll burrow into the ground to birth a colony); and overlooking it all … Well, the CEO analogy—a role seemingly fit for the queen—is tough.

  There is no centralized brain monitoring castes. No cosmic instructions to conquer the world à la Saul Bass’s film Phase IV. Nor are there the obedient soldier drone ants that Zeus transformed into the Trojan fighters known as Myrmidons. Ants are remarkably, systematically collective creatures. And studied closely, the revelations of ant communication have given us faster travel routes to Saturn and may reveal synaptic mysteries in the brain.

  From the Gospel of E. O. (Wilson, that is): “Ants are everywhere, but only occasionally noticed.”

  Across the world there are groups of women and men walking around, heads bent, pondering the fossorial life that teems below their steps. Searching for what E. O. Wilson calls “ecological juggernauts.” Without a doubt the most widely recognized myrmecologist (in layman-ese: an ant expert) is E. O. Wilson. Over 16,000 species of ants have been identified. Half studied intently. And never as in-depth as by the famed scientist. What’s there to be said about ants? Well, E. O. Wilson and Bert Hölldobler’s Pulitzer Prize–winning book The Ants carries 7.2 pounds3 of information, according to my neighbor’s bathroom scale. (The book Journey to the Ants is a summarized version of that.) Over the decades, E. O.’s oeuvre has presented remarkable discoveries about animal communication and habitat conservation. The Alabama-born biologist even captured part of his early childhood—a period in time he was nicknamed “Bugs”—in his novel Anthill. Through his time at Harvard, E. O. influenced a spectrum of scientific fields, coining such terms as “biodiversity” and propagating previously controversial ideas like “sociobiology.” The social qualities of ants and other insects even stumped Charles Darwin. The brood care of honeybees and termites, which among other things involved individual insects remaining sterile for group outcomes, could be “fatal to [Darwin’s] whole theory.” But then Darwin considered that perhaps natural selection operated on a familial level too. In this case, sterile bugs supporting their fertile relatives made sense.

  From the Gospel of E. O.: “The olfactory world of the ants is as alien and complex to us as though these insects were colonists from Mars.”

  Since 1953, E. O. Wilson and other scientists have discovered more than 20 chemicals ants used to lay trails4 or—as French scientist Guy Theraulaz recently found—to saturate the dirt for colony construction blueprints. Myrmecologists have also observed ants utilizing what E. O. Wilson has called 10 to 20 “words” and “phrases” with each other. Colony recognition comes in the form of sensing nonvolatile hydrocarbons in the epicuticle contact pheromones, which look like a “waxy film” coating the ants’ body. In an almost tribal manner, initiates are inducted from birth with the distinct colony scent,5 a unique fingerprint profile generated internally in the form of these hydrocarbons.

  The most innovative ants are the leafcutters Atta cephalotes, first described by Danish zoologist Johan Christian Fabricius in 1818. Their division of labor is as clear-cut as an assembly line. The process begins in the birthing chamber, where the queen is tasked with laying a modest 30,000 eggs a day. Workers will coddle her for this effort by regurgitating food at her feet. Afterward, the caste system, determined by body size, is physiologically split into soldier ants (with large mandibles utilized the same way Kimbo Slice’s monstrous biceps once pulverized contenders); and media worker ants with serrated jaws for fragmenting leaves to later cultivate into fungus. At the end of the cycle is a chamber for refuse disposal, also called a midden, which composts dead ants for fungus fertilizer.

  From the Gospel of E. O.: “The competitive edge that led to the rise of the ants as a world-dominant group is their highly developed, self-sacrificial colonial existence. It would appear that socialism really works under some circumstances. Karl Marx just had the wrong species.”

  How such collective behavior evolved is a mystery. Genealogically, ants are related to wasps. They both belong to the insect order called Hymenoptera. The missing link between them was discovered in 1967—and E. O. Wilson nearly destroyed it. When the New Jersey amber piece containing two Ur-ants arrived at Harvard, Wilson eagerly ran to the department and in his overzealous enthusiasm dropped the 90-million-year-old sample on the floor.

  Fortunately, the two ants stayed intact. But these primitive ants didn’t end up shedding any light on behavior. In 1977, a living species called Nothomyrmecia macrops was rediscovered. These ants bore similarities to Mesozoic solitary wasps who began nests in the soil. And more recently, 100-million-year-old fossil records give evidence of cooperative, eusocial behavior in termites and ants. But learning how ants evolved into the 16,000-plus species known today requires tracing the subterranean ant nests of the past.

  * * *

  An anthill entrance is visually unassuming. But its true scope reminds me of Hugh Raffles’s concluding sentence in his anthropological tome Insectopedia: “The minuscule, a narrow gate, opens up an entire world.” Unlike the 30-foot-tall thermoregulation termite towers composed of soil, saliva, and poop that resemble the vast Gopuram temples found in India, ant nests are less conspicuous. Yet the underground cities are impressive all the same.

  To learn about the evolved sociability of primitive ants, it might help to examine the modern features of these buried colonies. No one has done this better than Florida State University professor Walter Tschinkel. According to Tschinkel, nests come in an array of geometric shapes and sizes
, creating “shaped voids in a soil matrix.” Using the same plaster6 found in an orthodontist’s office, Tschinkel fills the nests like you would a Jell-O mold, to later excavate and reassemble the hardened casts. Unearthed, the results vary. A common woodland ants’ nest with a workforce of 200, he says, has a “shish-kebob” design, that is, “flattened horizontal chambers” the size of oyster mushrooms connected by a narrow tunnel. But when it comes to the Florida harvester ant, Tschinkel unveils 150 chambers connected by spiraling, helical tunnels boring down 11 feet from the topsoil where the branches cluster and gather like a pixelated jellyfish. It can take 8,000 determined worker ants just four to five days to complete such a structure. Brazilian biologist Luiz Forti created a similarly difficult mold over a decade ago with an abandoned leafcutter colony and 10 tons of cement. A month later, the excavation revealed a “labyrinth of channels” extending 500 square feet, designed like a tertiary mycelium network sprouting dome-shaped chambers—a complex achievement that’s been compared to the Great Wall of China, but ants smoke that architectural feat. By taking these casts and finding other subsurface fossil nests and scanning them with 3-D morphometrics programs, scientists can show, as Tschinkel writes, “the course of [ants’ sociality] evolution through the ages.”

  Today, we can snake anthills with endoscopes—despite the ants’ feisty attacks—and reconstruct makeshift colonies that go beyond Uncle Milton’s Giant Ant Farm. In the BBC documentary Planet Ant, innovative scientists built a series of dirt-filled terrariums intricately connected with glass tubes like a Rube Goldberg crack pipe in order to watch the cogs and gears of a 1 million–strong leafcutter ant colony.7 Setting aside methods used since the 1950s, the Atta project was an approach to modeling grandiose colonies that didn’t involve plaster, concrete, or aluminum or make the ants homeless.

  “But to do it nondestructively, we just don’t have the resolution to do much with the data,” says Kim Drager, a University of Illinois student. “You can get density versus depth,” she says, but the fine details offered by castings eclipse what GPR data can do for now.

  Drager’s PhD adviser gave her the intellectual freedom to become a hybrid myrmecologist and edaphologist (in layman-ese: a soil expert). Her gung-ho enthusiasm and youth were reflected by the Jackson Pollock–like pants she wore at the Entomological Society of America conference, where she gave a presentation on making casts like Walter Tschinkel and exploring their design implications on the landscape’s geomorphology.

  “Soil is a living, breathing thing,” Drager tells me. “It interacts biotically, abiotically, it’s a carbon sink—without soil, we wouldn’t have agriculture. We wouldn’t be alive.” Still, I’m not too surprised when she tells me little research exists on how insects impact dirt. What’s available is summarized nicely in a 1990 paper entitled “The Role of Termites and Ants in Soil Modification.” The researchers detailed the increase in carbon, nitrogen, phosphorus, and potassium in areas surrounding a nest due to soil-mixing. The ants regurgitate rich nutrients from below into the topsoil. Ultimately, the researchers found the significance of these soil habitats “difficult to assess.” However, the implications, says Drager, could be grand. Arizona State University geography professor Ronald Dorn has measured the calcium-magnesium, rock-forming silicate minerals in several ant colonies for the past 25 years. He found that areas with ant nests increased carbon dioxide capture into rock 335 times faster. That’s enough absorption to affect climate change’s rise in temperature, which could partially explain how the Earth began cooling 50 million years ago. “It’s also species-specific,” says Kim Drager. “[Ants] have different modifications that they can do. For example, to keep rain out of their nests.”

  From the Gospel of E. O.: “The first law of ant colonial existence is that the territory must be protected at any cost.”

  Their mounds, Drager says, appear to have hydrophobic properties, which prevents the interiors from flooding. While the mound disappears relatively soon after nest abandonment, “the subsurface nest will persist for hundreds of years or more in the soil.” And they become conduits for water flow. Modeling how their porosity channels water into the ground may help us understand the rate of slope erosion over landscapes. “Their nests are actually a reflection of their life history,” adds Drager. It turns out that they are also possibly a reflection of ours.

  One 1990s study of ant behavior actually revolutionized our world with its ant colony optimization (ACO) algorithm. Besides using visual landmarks for navigation, ants leave pheromone trails toward food sources, outlining directions. As more ants take the quicker path, the pheromone (from the Greek meaning “carrier of excitation”) reinforces shorter, faster routes, while wanderers find other potential leads and let the useless trails evaporate. An analogous system was programmed into algorithms in the 1990s by Marco Dorigo and two other Italian scientists to solve the traveling salesman problem—a way of graphing the most efficient possible routes to distance sites. “An increase in the computational complexity of each individual,” they write, “can help … face environmental changes.” Their adaptable, “autocatalytic behavior” went on to improve the efficiency of the delivery and transfer methods from billions of different options. This created route efficiency for a bevy of industries, including commercial shipping. It was also used on the 1997 Cassini space probe. Yes, thanks to ants we have faster routes to Saturn.8

  Wired with such naturally derived sophistication, these eusocial ants can possibly improve Internet traffic. A study by Stanford ecologist Deborah Gordon and computer scientists found the “evolved feedback-based algorithms” in harvester ant colonies mirrored the Internet’s transmission-control protocol (TCP)—a “state-ful” way to manage data congestion online without a central control hub. To elaborate: the TCP algorithm finds “available bandwidth and efficiently utilizes it for the duration of data transfer” to avoid congestion. Should a link break, a “time-out” occurs, which usually appears in your browser window with an exclamation mark.

  Similarly: when ants hunt for seeds, the rate with which they return home either decreases or increases the number of foragers leaving the nest so as to maintain steady traffic. “When foragers are prevented from returning for more than about 20 minutes,” the study reads, “foragers stop leaving the nest.” This system, dubbed “Anternet,” has existed for millions of years within ant colonies. According to the Stanford study “Anternet: The Regulation of Harvester Ant Foraging and Internet Congestion Control,” their feedback algorithm may be easier to implement than the current TCP. It leaves me wondering what other revelations ants might have in store for us.

  One possible avenue may reveal more about the network connection of our own neurons. Currently, Deborah Gordon is working with a computer scientist at the Salk Institute to trace the “network of trails” a certain ant species makes on vines, leaves, and trees in the tropics. As vegetation shifts around, say by a tree branch snapping, the ant network rapidly responds, she says. In this sense it’s one network repairing itself within an ever-changing environmental network. There’s a similar issue when it comes to synaptic pruning in our minds. “We know [the connections] change in response to changed experience,” Gordon tells me on the phone, “so we’re looking at the analogy in the resilience of these networks … It seems we’re going to find a lot of interesting natural algorithms in ants.” Engineers might continue the trend of using them in unforeseen ways.

  Gordon has spent nearly 30 years watching ant interactions, traveling every summer to Arizona to monitor a growing plot of harvester ant colonies. It’s led to some rather controversial theories.

  From the Gospel of E. O.: “The exploration of caste and division of labor in ants is in an early stage, and many surprises surely lie ahead.”

  Since the 1960s, common opinion had it that specialization in body size was directly associated with an ant’s job task. “Minor” and “media” workers and “soldiers” were designated to nursing, cleaning, foraging, and guarding, wi
th the occasional reassignment to other duties as they got older. This process is known as age polyethism. But for the past 20 years we’ve found that, much like us, as Gordon notes, “an individual’s behavior changes in response to shifting conditions and colony needs.” Organization is more complex than previously thought.

  “The daily round of an ant colony is made up of large numbers of brief, simple interactions,” writes Gordon in her book Ant Encounters. “The outcome is a miracle of fine-tuning.” Besides laying down pheromones for food highways, ants communicate via rapid-fire, Morse code–like antennal taps as they stream past each other to “adjust colony activity.” It’s the same feedback response as with the TCP algorithm. To test her theory, Gordon marked harvester ants in the 1990s, assigning different colors to ones doing certain tasks.9 “Then they showed up doing something else,” she says. She calls “division of labor”—an idea introduced by Adam Smith in 1776—misleading. “If one unit cannot finish a task,” she writes in one paper, “another can take it over with an equal probability of success. This is not possible with division of labor because shoemakers have not learned to make candles.” Their complexity goes beyond cogs in a clock, beyond independent parts. The system, like a brain or our daily life, is so much more. Her view on task allocation has yet to be widely embraced by the myrmecology community. Count E. O. Wilson—whom she’s met several times—in that category.

  “Have you two ever discussed task allocation versus division of labor?” I ask.

  She gives a curt “Yes”—and chuckles a bit.

  “What was that conversation like?”

  Pregnant pause. “Um, well—um. I think Wilson found my work to be a challenge to his work,” she laughs. But it’s a worthwhile dispute.

  From the Gospel of E. O.: “All of ant behavior is mediated by a half million or so nerve cells packed into an organ no larger than a letter on this page.”