Adventures Among Ants - Mark W. Moffett [9]
I could attest personally to the effectiveness of that approach. While watching the frog, I’d made the mistake of standing in a throng of marauders. The sheer volume of the minor workers’ bites was enough to drive me away, with one major lacerating a fold of skin between my fingers.
This scale of operations brought to my mind the most infamous raiders of all: the army ants.3 As a teenager in America’s heartland, far from any jungles, I had devoured popular descriptions of army ant swarms killing everything in their path. The stories often relied on florid writing, most famously in an unforgettable story by Carl Stephenson, first published in a 1938 issue of Esquire, “Leiningen versus the Ants”: “Then all at once he saw, starkly clear and huge, and, right before his eyes, furred with ants, towering and swaying in its death agony, the pampas stag. In six minutes—gnawed to the bones. God, he couldn’t die like that!” Although this is hyperbole, army ants do have an appetite for flesh and a coordinated battle plan that depends on sheer force of numbers.
Like many army ants, marauders have no stingers. Rather than incapacitating prey with stings, they mob it. This gang-style predatory attack is just one element of both ants’ complex routine. How much deeper did the resemblance go? I knew that currently there are as many species of ant as there are of bird—perhaps 10,000 to 12,000—and that the marauder and the army ant are no more closely related than the hawk and the dove.
Convergence is the process by which living things independently evolve to become alike, as a result of like responses to similar conditions or challenges. The wings of bats, birds, and bugs are convergent because they are limbs that have been independently modified to function in flight; the jaws of humans and the mandibles of insects are convergent because both can be used to hold objects and chew food. If the marauder ant and army ants proved to be alike in how they hunt and capture prey, it would be a similarly marvelous example of evolutionary convergence. That day in Sullia as I watched the ants dispatch that unfortunate frog, I made a decision that would affect the first years of my budding professional life: I would study the kill strategy of the marauder ant. I would make that my quest.
FEEDING THE SUPERORGANISM
Standing in a Sullia field on a tepid afternoon, with Raja’s guitar providing an incongruous musical accompaniment to the massacre at my feet, I felt like a general observing his troops from a hilltop and trying to make sense of the skirmishes below. My brain was whirling: one moment, trying to picture what it’s like inside one of those tiny, chitinous heads; the next, envisioning all the ants at once, forming a kind of arm flung over the ground with fingers that were rummaging through the soil and low plants.
The nineteenth-century philosopher Herbert Spencer was the first to treat in detail the simultaneous existence of these two levels, individual and society, and in 1911 the ant expert William Morton Wheeler came up with the term superorganism to describe ant societies specifically. Both men saw an ant colony not merely as an individual entity, as one might think of a bank or a school, but more specifically as the exact equivalent of an organism.4 They could readily make this point because others had already described the human body as a society of cells.5 The superorganism concept took on real meaning for me as I watched marauder ants. Before coming to India I had read an essay by the physician and ant enthusiast Lewis Thomas, who took Wheeler’s writings to heart:
A solitary ant, afield, cannot be considered to have much of anything on his mind; indeed, with only a few neurons strung together by fibers, he can’t be imagined to have a mind at all, much less a thought. He is more like a ganglion