Adventures Among Ants - Mark W. Moffett [133]
Argentine ants, shown here in Argentina, move continuously between nests within a colony, a fluid lifestyle that constantly mixes the population.
16 armies of the earth
Weaver ants attain colony sizes of a half million; certain driver ants, possibly twenty million or more. But we close this book with the Argentine ant, whose dominion is the granddaddy of them all—colonies that can span hundreds of square kilometers. Knowing that as colonies grow larger, their inhabitants tend to become more aggressive, I had anticipated that colonies this large would have an almost unlimited capacity for bloodshed, and I was on the brink of witnessing their battles.
It was the fall of 2007, and I was in southern California with David Holway, an energetic associate professor from the University of California, San Diego. With us was Melissa Wells, my partner in adventure since we had met nearly a year earlier, at the counter of Pearl Oyster Bar in Manhattan. A redhead with a swimmer’s strong body, Melissa had a hunger for exploration (and for oysters) that matched my own. Though she proclaimed a preference for elephants, she thought chasing ants was pretty nifty, too. I had taken her to Laos and Cambodia, where she produced a video of me with the weaver ants, and now we were en route to what, I assured her, was the largest battlefield on Earth. Our visit would lead me to conceive of a new kind of superorganism, one not limited by the corporeal boundaries of time and space or the ordinary lines between individual, society, and species.
But at first Melissa and I must have looked doubtful as David drove past the suburbs along Del Dios Highway in San Diego County. He turned off in Escondido, a secluded coastal development north of Del Mar. Navigating through well-tended streets, he finally parked along a curb and proclaimed, “This is it!”
Dead bodies of Argentine ants piling up along the battle lines between the Lake Hodges Colony and the Very Large Colony in Escondido, California.
We were surrounded by tidy homes and hedges. Melissa shot me a quizzical look, but David urged us to our knees at the curb, and there, in a bare patch of dirt and continuing over the concrete, we saw a finger-wide, chocolate-brown belt of tiny dead bodies, piled up by the thousands. The heap of corpses continued out of view, hidden by the undergrowth. From what I’d read, the battlefront could extend for miles. David explained that thirty million ants die each year in border skirmishes between the Very Large Colony and the Lake Hodges Colony. That’s a casualty every second.
“Last night’s rain shower may have broken up the fighting,” David warned us.
That may have been the case, but already the battle lines were reforming. Trails of ants, converging from all directions, led the troops over the remains of the dead. Scanning the action through my camera, I gave Melissa and David the blow-by-blow on dozens of fierce confrontations. Most started one-on-one, with a slow and meticulous approach followed by a thrust-and-grab. Atop the corpses, pairs of workers pulled on each other, indefatigably, for minutes (and for all I knew, hours) on end. Here and there, a third or fourth worker joined in. I focused my camera on a group of three ants pulling on another that was already missing an antenna. As I watched, a hind limb tore free. The worker who wrenched it off stood for a moment as if surprised at her success, the leg hanging from her jaws, before dropping it and inspecting her adversary’s stump.
This intimate view was reminiscent of the warfare of species such as the marauder ant and the weaver ant, where workers use a similar rack spreading technique. But while marauder ants fight only during the few hours when they happen to encounter another colony in a raid, and weaver ants engage in skirmishes that can go on intermittently for weeks, the Argentine ant battles ceaselessly. The ants actively police every centimeter