Kill Decision(19)

Weaver ants—Oecophylla longinoda. Along with mankind they were one of the few extirpator species on earth—meaning they deliberately sought out and destroyed rival organisms (including their own species) to maintain absolute control of their territory.

McKinney zoomed the camera in on a growing knot of weavers, watching as dozens of workers swarmed a much larger, black ant—a Dorylus major, the warrior caste of the driver army ant (which the locals called siafu). The monstrous black ant had one of the weavers in its mandibles, but following a timeless script, the much smaller and faster weavers grabbed hold of their enemy, first immobilizing the massive intruder—and then tearing its legs off. They dropped it among the dead and moved on to their next victim.

Defeating a siafu army ant colony in battle was no mean feat. Here in Africa, even humans steered clear of siafu, which occasionally swarmed in wave fronts twenty million strong into huts and farms. Anything that could not escape their grasp would die. There were authenticated accounts of siafu killing humans who’d passed out drunk, unattended infants, and goats or cows that were tied in place. First suffocated by thousands of ants crawling into their mouth and lungs, the strangled victims would have their flesh removed in hours, leaving only bones behind. There was no stopping the swarm. You just had to get out of the way. And yet, as fearsome as they were, even siafu army ants fled from the weavers.

Weavers were so aggressive that McKinney would hear them in their multitudes, drumming their legs against tree leaves in alarm, sounding like raindrops as she walked through the mango orchards. Gathering their troops. Collectively, they dominated the treetops of Africa—while their close cousins Oecophylla smaragdina dominated the trees of Asia and Australia. What made them even more fascinating to McKinney was that their reign had already lasted more than a hundred million years. Human civilization was barely a blip on their radar screen.

Weaver society was so durable, so adaptable, that these ants had survived ice ages, extinction-level events—like the asteroid impact that doomed the dinosaurs at the end of the Cretaceous period, sixty-six million years ago. In fact, more than merely surviving, the weavers had thrived. In terms of biomass, they now rivaled that of humanity itself. In numbers they were counted in trillions. They were one of the most successful and enduring species on the face of the planet. That was one of the reasons she had spent her adult life studying them. There was an ancient knowledge of sustainability here on a scale humans could only aspire to. And they were fascinating in so many other ways.

McKinney had originally been drawn to myrmecology because of social insects’ unique evolutionary strategy; where most organisms had a single body, Hymenoptera—the order of social insects that included wasps, bees, and ants—were in effect a single organism consisting of millions of separate bodies. The physician Lewis Thomas once described ants as “a brain with a million legs.” It was like being able to send your hand to go get things while you were off doing something else. The great myrmecologist E. O. Wilson proposed that ants were a “superorganism”—an organism that transcended the limitations of a single body to enact a collective will. And that will had an intelligence superior to that of the individual ants themselves. Precisely how this occurred was still unknown, and it was a mystery that McKinney had dedicated her career to unraveling.

Studying the screen, she keyed observations into her laptop and spoke via speakerphone to a graduate student several miles away. “Mike, check the lens on camera nine. There’s an occlusion that’s confusing the tracking software.”

“Got it. Rich, can you move the lift closer?”

Another voice came in over the line. “There in a sec.”

“Thanks.”

McKinney zoomed the image out, displaying dozens of thumbnail video insets on the panoramic HD monitor that, when tiled together, outlined an entire mango tree as a three-dimensional model. She rotated the model as though it were a video game—the difference being that the tree was real and the images real-time. The tree stood on the verdant hillsides near the Marikitanda Research Station, where McKinney ran her field lab. The mango tree’s entire surface was being recorded in real time from dozens of separate digital video cameras placed on scaffolding around it. Software was stitching the imagery together into a single live 3-D image wrapped around the tree. Just one nest out of this colony’s domain of a dozen trees, covering nearly eight hundred square meters of ground with nearly a half million ants in all. It had taken years of research and grant applications for her to get this system up and running—and to obtain such up-close and complete imagery of an entire weaver nest in real time. Of the superorganism in motion. And all to test whether her software model of weaver society was accurate. And, in turn, whether it could form the basis of a general model of Hymenoptera intelligence. That, in turn, might reveal secrets as to the very nature of intelligence itself.