Anthill

by Edward Osborne Wilson

  Raff nodded enthusiastically. "Yessir," he said.

  "I know your senior year is still a long way off," Needham continued, "but believe me, you can never have too much time to do a good honors thesis. You might even be able to publish a paper in one of the entomology journals. I'd be glad to advise you if you give it a try. But of course that's just a suggestion. There are a hundred things you might want to do more, at Nokobee, or around here, or anywhere. But does that sound at all interesting to you?"

  Raff said, "Yessir, you bet it does, it really does. I think I'd like to keep working on the anthills."

  When they met later in his office, Needham pressed his earlier suggestion. "This is an interesting species. We're really just beginning to study ants properly. And don't let anybody tell you they aren't important. Keep in mind that ants not only rule the insect world, but societies like the ones at Nokobee are the most complicated on earth next to humans."

  In effect, Needham had said to Raff, like a prince of old to an explorer, Go out and search. Everything you find will be important. Record it. Then come back here and report it, to me, and to all.

  Needham knew what he was doing. He understood that nothing propels the postadolescent mind more powerfully than to be told by someone in authority, You do this well, you like doing it, it is interesting and important. So I hereby commission you to take charge. Pursue this as far as you are able. Make it your special mission.

  Such was the spirit, Needham knew, that has driven much of the history of biology. Carl Linnaeus, the great eighteenth-century Swedish botanist and founder of biological classification, profited by it. He instructed his best students--his "Apostles," he called them--to be his eyes and hands as they visited foreign lands. And so seventeen gifted young men went forth variously to the Levant, Japan, South America, and the North American colonies, to be the first to collect the plants, to study them, and to bring specimens back to Europe for further research by all generations into the future.

  When Charles Darwin was twenty-two years old, he was told, in effect, Charles, we know you love natural history. There's a job open, as naturalist on HMS Beagle. You can have it. We want you to travel on this ship to South America and learn all you can about the geology, plants, animals, and people. Then come back and tell us what you found. In the following five years the great naturalist deduced the geological origin of atolls, he collected countless new species of plants and animals, and not least, and to the immense benefit to science, he invented the theory of evolution by natural selection.

  Raff's parents knew nothing of this principle of apprenticeship when he told them he would be studying ants at Nokobee. Indeed, Marcia was baffled by his choice of subject.

  "I don't understand it, Scooter. I know it's for your education, and I'm very happy that Fred Norville and Dr. Needham have taken you under their wings. But what good are ants? Wouldn't it be better to take some subject connected to medicine, or maybe agriculture?"

  "There are a whole bunch of reasons, Mom. I want to do real research out at Nokobee. I know the place real well--you know that. I've been watching those ants at Dead Owl Cove. Uncle Fred said he wanted you and Dad to know that the research is going to be important. Ants may be small, people laugh at them and all, but you know, they're a huge part of the environment. They're the most social animals in the world. Anybody who knows anything knows we learn a lot about social behavior in people by studying things like that."

  "Well, now," Marcia said, "I guess the professors know what they're talking about. If they don't, who does? And it's just wonderful that you're going to be able to do your study right here at home."

  Ainesley didn't much care what Raff did. What mattered to him was that his son was a college student and had a real future ahead of him.

  "Hell, Scooter, I don't know what this is all about, but I'll even go out to Nokobee and help you if you want me to, whenever I get a little time off from the store. I'll bring along a shovel."

  Soon after Raff began the actual studies, his new friends at the Bug Bash began calling them the Anthill Chronicles. Bill Needham's engagement in the project increased with time, as he lent his own expertise and insights to the events unfolding in the population at Dead Owl Cove. Month by month, whenever Raff brought in new observations, Needham helped him piece them together with whatever was known of the social behavior of other kinds of ants.

  18

  THREE YEARS PASSED as Raff commuted between Clayville and Tallahassee. When he turned in his senior thesis, two months before graduation, the Anthill Chronicles had matured into an epic of miniature civilizations. The foibles of ants, Raff learned, are those of men, written in a simpler grammar. Compared with those of humans, the anthill cycles are short in duration, instinct-driven, and hence truly ordained by fate. The ant societies proved different in most fundamental ways from those of humans--of course--yet also convergent to them in other, also important ways.

  The half dozen committee members of the Department of Biological Science who reviewed the thesis judged it as one of the best they had ever seen--in conception, in originality, and in execution. Raff dedicated it to the two sponsors of the research.

  For Professors William A. Needham and Frederick Norville, whose generous help and dedication made this study possible.

  Bill Needham and I both valued that simple acknowledgment as much as any we'd received in books and journals from our fellow professional scientists.

  What Raff found deserved to be preserved, and I set out to do so, with Bill Needham's assistance, shortly after Raff's graduation. We omitted Raff's measurements and tables, and translated his sometimes stiff language into less technical form. The merit of this account, to follow, is that it describes what actually occurs in such anthills during their remorseless struggles and wars. It presents the story as near as possible to the way ants see such events themselves.

  At another level, in my experience, nothing expresses better than the anthill epics the energy and dynamics of all life in the Nokobee tract, and for that matter other fragments of the living natural world left for us to observe.

  At the very start of the study Raff had fixed his attention on the large colony at the Lake Nokobee trailhead. This was the first anthill encountered upon arrival at the lake, and the one on which he had taken the most notes in earlier years. Naming it the Trailhead Colony, Raff decided to make it the prototype for his thesis studies. He chose wisely to record its habits and social behavior as thoroughly as possible without digging it up or disturbing it in any other way. Needham suggested further that these observations would serve as a baseline for later studies, including those of other colonies scattered over Dead Owl Cove. A more nearly complete picture might then be drawn for the whole species.

  Among Raff's earliest childhood memories was the Trailhead Colony as a dominant presence in the open space of the picnic area. On every warm rainless day, its foragers patrolled ten yards or more from the nest mound. And several times an hour, some of them returned to the nest entrance bearing various fresh prey, fragments of scavenged dead insects, nectar from plants, and the sugary excrement of sap-sucking insects.

  When Raff began a more than casual study late in the previous year before coming to Florida State University, he noticed that the activity of the Trailhead Colony had declined sharply from the high intensity of its past. Many fewer foragers ventured out of the nest, and proportionately less food was coming in. When Raff went so far as to prod the mound surface with a trowel, only a small number of defenders rushed out to mount a defense. Something was wrong with the mighty Trailhead Colony.

  "I think it's sick, and it's getting worse," he said at a Bug Bash, "and I have no idea why."

  Bill Needham nodded. "Sounds like the queen has died on you. No queen, no eggs, no more larvae. The colony doesn't need as much food, so the workers are staying at home. Sort of like old folks at a retirement community."

  "But why should the whole colony quit like that?" Raff said. "Are they having a memorial s
ervice or something?" That brought approving laughter from the Bashers, a rare tribute to a beginner like Raff.

  "Well," Needham said, "you've got to understand what a powerful stimulus a queen is to all the workers. When she goes, they're less responsive. Something goes out of their spirit--so to speak."

  Circling an index finger in the air, as he often did when he was about to introduce a new idea, Needham asked, "How long have you been watching that colony anyway?"

  "Well, believe it or not," Raff replied, "since I was a little kid, I'd say ten years or so. It's hard to miss when you first get to the trailhead."

  Needham reached for a volume on the shelf next to his desk, searched the index, opened to a page, and pointed to an entry. He said, "That's no surprise. In ants similar to your species, we have records of the mother queen living over twenty years."

  "Twenty years? That's older than I am."

  "Yep. I'll admit that's an amazing life-span for an insect," Needham said. "It's longer even than for the seventeen-year locust. But it does occur in the queens of a few kinds of ants. My guess is that it's a world record for insects. On the other hand, very few of the workers live more than two or three years. That's true even though they're all the queen's daughters, and all have her same heredity. Now, that's a real strange situation. Longer than that must seem like an eternity for them. They exist, you might say, in a mental world that's got no beginning or end. They have no concept of their mother queen dying. She's just always there. Even when it finally happens, even the retinue that takes care of the old girl doesn't realize at first that she's dead. I suggest you keep a close eye on that colony."

  The death of the Queen was to have consequences critical to the fate of the Dead Owl Cove ants, across the five seasons their history was recorded by Raphael Semmes Cody. For that reason Needham and I chose to place this event at the opening of the Anthill Chronicles.

  IV

  The Anthill Chronicles

  19

  IT WAS TRUE. The Trailhead Queen was dead.

  In the first days there had been no overt sign that her long life had ended. There was no fever, there were no spasms, no farewells. She simply sat on the floor of the royal chamber and quietly died. As in life, her body was prone and immobile, her legs and antennae relaxed. Her stillness by itself failed to give warning to her daughters that a catastrophe had occurred for all of them. She lay there in fact as though nothing had happened. She had become a perfect statue of herself.

  The deception was the result of the way the bodies of insects decay after death. Where humans and other vertebrate animals have an internal skeleton surrounded by soft tissue that quickly rots away, insects are encased in an external skeleton. Their soft tissues shrivel inwardly into dry threads and lumps, but their exoskeleton around them remains, a knight's armor fully intact long after the knight is gone.

  Hence the workers were at first unaware of this mother's death. Her quietude said nothing, and the odors of her life, still rising from her, signaled, I remain among you.

  She smelled alive.

  The deception was made easier because in life she had never given orders or led them in activities of any kind--even though her brain was fully programmed to perform all of their tasks if she chose.

  She was to all purposes a winged wasp who lived in a neutered wingless society. Yet the only initiatives she ever took were all in a burst at the beginning of her adult life--with approximately twenty years left to go--when she left the colony of her birth, abandoning along with it her mother and sisters. She mated then, once for all time--no more sex for her--and started a new colony of her own. Furiously, during a very short period of activity and alone, she performed almost all of the instinctive behaviors of a female of her species, and on top of that the same labor as sterile workers of a developed colony.

  The hereditary programs were there, in the sense organs of the Trailhead Queen and in her nerve circuitry, all expressed in the required correct sequence of her actions. These programs faithfully repeated the routine followed by the ancestral wasps that evolved into the first social ants as they crawled among dinosaurs over a hundred million years ago.

  Leaving the nest of her birth to start this process, she first spread her four membranous wings and flew into the air. There she joined a swarm of flying males and other virgin queens. One of the males was able to catch her. He clamped his legs around her body, and the couple spiraled down to the ground. On landing, he used large claspers at the rear end of his body to hold their genitalia together and complete the insemination. Within five minutes the act was finished, and the Queen shook the male loose. All of the sperm she received flowed up into a special bag-shaped organ in her abdomen to stay there until called on to fertilize more of her eggs. That might be years into the future. Each sperm was endowed with a potential life-span equal to her own.

  In contrast, the father of all her children was programmed to die almost immediately after the mating. The only thing he had ever done was accept meals regurgitated to him like a nestling bird by his sisters, and wait, and wait some more, and finally take the one short flight from his home followed by five minutes of copulation.

  The male had started his life as an egg laid by the Queen of the mother colony. The egg hatched into a grub-shaped larva, which was fed by the all-female nurses. Upon reaching full size, the larva metamorphosed into a pupa. This final immature stage was encased in a soft, waxy, temporary exoskeleton with the form of an adult and three body parts--head, thorax, and abdomen. A pair of antennae and three pairs of legs sprouted from the body. Inside, the masses of undifferentiated tissue, protected by the waxy outer skeleton, grew into his final internal organs.

  When the transformation was complete, the outer layer was stripped away and eaten by the workers, and the adult male stepped out, complete with wings, large eyes, massive genitalia, rudimentary jaws, tiny brain, and the one big purpose programmed in his tiny brain followed by quick death.

  In short, the male was no more than a guided missile loaded with sperm. His life's work would be a single ejaculation. Up to the climactic moment, he had been a parasite in his mother's colony, a layabout fed and groomed by his sisters. He performed no public service. After his world-defining five minutes, he was left with only one instruction that would be enforced if necessary by his sisters. Don't come back here. Just die.

  He would not even try to return to the nest. He had no chance at all of survival. A delicate creature, he was not provided with defenses. He had no way to find food, or feed himself if he stumbled across some. He had been issued a one-way ticket. He would die by dehydration, or crushed in the beak of a bird, or chopped into pieces by the jaws of an enemy ant, or, less quickly, pierced by the bloodsucking proboscis of an assassin bug.

  To escape the same fate, the newly mated future Queen of the Trailhead Colony, full-brained and powerfully muscled, hurried to find shelter. She had to get back underground as quickly as possible after receiving her sperm load. First, however, she had to take a few minutes to shed her four wings. To do that she simply bent her middle legs forward, pressed them against the base of the wings, and snapped them off. This mutilation caused no injury to the rest of her body. It caused no pain. From the start the wings had been lifeless films and struts of chitin, joined to the body in a way that made them easy to break off painlessly and then discard.

  The Queen was a parachutist that slipped her harness upon landing. Now she could move more quickly to avoid ants, spiders, and other predators hunting around her in the grassroots jungle. She was fortunate to come upon an open space between grass clumps, a small, ant-sized clearing at the Lake Nokobee trailhead. By luck she had found it an ideal site. If she could build a nest there, it would be her home for, perhaps, twenty years. She set out at once to dig a vertical tunnel in the sandy clay soil. Her movements were swift and precise, and within minutes she had deepened the shaft to more than her body length. It provided some degree of protection, but needed to be completed as quickly as possib
le. She had to hurry. Her life remained in constant danger; there was not a minute to lose.

  At a predetermined depth, which she measured by the time it took her to climb up and down the shaft, the young Queen turned to the side at the bottom and began to excavate a wider space. She continued until she had fashioned a round chamber about three times wider than the vertical shaft. Her safety was now enhanced but far from ensured. Predators and marauding ants could still climb down the shaft to attack her. At least now the enemies would be confined to a narrow space by the walls of the shaft and forced to confront the young Queen's thrusting sting and snapping jaws head-on before they could reach her vulnerable body.

  With this much achieved, and as the shadows of the surrounding pines lengthened across the trailhead, she had beaten odds of about a hundred to one. For every hundred young queens leaving the mother nest in order to be mated and start a new colony, only one at the end of the day now sat in the bottom chamber of an incipient nest.

  Yet in spite of this huge achievement, and no matter how securely she had constructed her home, the odds against final success were still stacked against her. The chance of progressing from being the architect of a nearly excavated nest to being the mother of a large, mature colony was also about one in a hundred. Thus the Trailhead Queen would be statistically the single one in ten thousand who flew from the mother nest and went on to finish the entire process. She alone would enjoy a long life in the deep royal chamber of a mound nest. Defended by an army of fierce daughters, she would be as safe as any insect in the whole world could expect to be.

  Even with the excavation of the first chamber complete, the Trailhead Queen still had heavy work ahead. First, she laid a small cluster of eggs on the earthen floor. These tiny objects she was compelled to lick continuously. It was an urgent task, because to the peril from enemies above was now added the threat of bacteria and fungi teeming in the soil all around her. If the eggs were not regularly cleaned and coated with antibiotic saliva, they would be soon overgrown by an invading mold and consumed. And from a single bacterium in the soil excavated by the Queen, millions could proliferate on any ant tissue left unprotected.