Adventures Among Ants - Mark W. Moffett [59]
I took off for an hour to look for ants along the path to Cameroon, unable to stop thinking about how an aggregate of army ants, using the interweave of their columns and scents, explores the world much as an organism does. My mind turned to the driver ants’ blitz of the carpenter ant colony. Two young men strolled into view, baskets filled with dried meat balanced on their heads. Judging from their stares and whispers, I must have been an odd sight indeed.
After years of living on foreign soil, I have developed a method to deal with this reaction, based on the assumption that, since I am the center of attention anyway, I might as well make things interesting. Whether faced by a crowd at a bus stop in Nepal, by kids leaving school in a mountain town in Bolivia, or by weary foot travelers in Nigeria, I walk back and forth like a professor in a class, carrying on out loud about whatever is on my mind.
“The swarm raid rolled over the carpenter ant nest as if it were nothing,” I said to the two astonished villagers. “Just a tiny minority of the driver ants were involved in the kills. What does that tell us?” I turned dramatically to the young men, who were grinning at my animated speech. They gave my hand a shake and continued on their way, chattering.
My brief soliloquy led me to the obvious conclusion. The driver ant raiding enterprises were superorganism-level organs geared for much larger confrontations than those I had witnessed so far. Two days later, this suspicion was confirmed.
7 clash of the titans
Early on my first evening at Gashaka-Gumti, after the long day’s search for driver ants, I collapsed on the hard earth outside my room at the field station and contemplated the parrots flying overhead. But then I became aware of movements in the grass, and I turned my head to witness a remarkable sight: a row of handsome, 2-centimeter-long cylindrical Pachycondyla analis workers, right next to my face.
Scientists studying Pachycondyla have determined that raids of species like the one at Gashaka don’t proceed like those of driver ants and other army ants. Rather, they are led by an individual that has scouted a promising target population of termite prey and recruited a couple hundred workers to harvest it. I was witnessing that now. Traveling in a compact squad 2 meters long and two to four ants across, the workers in front of me marched at a steady pace of 1 meter per minute, following the leader to dinner. There were no stragglers. Compared to the swarm raids of the army ants, this raid seemed leisurely and orderly in the extreme—another example of how ants in smaller societies move slowly and with care.
Eventually the ants entered the brush, where I couldn’t follow. Circling the field station, I saw more columns sallying forth, one from each of several nests that were apparently operating on a tight and synchronous schedule. Thirty minutes to an hour later, the ants reemerged from the brush and headed home in identical formations. Only now, each one held several termites, stunned by the toxins from the ant’s stinger, bundled between her jaws.
Two nights later, a feeble column from the Dorylus rubellus driver ant colony near the kitchen, retracing the route taken by the raid of two days before, passed next to one of the Pachycondyla nests. Some of the rubellus ants stopped in the open-jaw guard position, preventing the much larger Pachycondyla from departing on their raid. Every minute, one or two of the besieged Pachys (as ant experts call them) stuck her head out of the entrance to the nest and jabbed at the tormentors. Occasionally a Pachy succeeded in grabbing a driver ant and pulling it below, where I could just make out the workers tearing it apart.
Every fifteen minutes or so, there was a surge of activity in the driver ant column, and rubellus workers poured down the Pachy