Adventures Among Ants - Mark W. Moffett [62]
All day and through the next night, the driver ants continued to drag the termites to their nest. But where were they coming from? Scanning the surrounding landscape, Caspar and I eventually found two more columns of the same driver ant colony in the savanna. Judging by the differing proportions of the small worker, soldier, and queen termite castes being moved along each of the three highways, it seemed they represented three separate attacks, on either different termite colonies or different battlefronts within the same termite nest. In the end we estimated the ants hauled away at least half a million termites, large and small—several flaccid kilograms in all.
Driver ant workers investigating a termite fungus garden presented to them in an experiment in Gashaka, Nigeria. The same colony had attacked a large Macrotermes termite nest at this site.
An intriguing story, but how incomplete. In science, we learn by bits and pieces, leaving others to unravel further details. I could only guess at the scene that had unfolded somewhere beneath our feet. During the underground portion of their forays, the driver ants must have clashed with termite soldiers ganged along narrow access routes to their castle in much the way Pachy ant workers had shielded their nest entryway. But in this case the driver ants broke through and launched into wholesale looting of the corridors beyond, transforming a steady raid advance into a focused attack that continued for hours.
Since I hadn’t witnessed the original killing spree, I decided to reconstruct it. I took a fungus garden from the termite nest that Caspar and I had dug up and deposited it next to a file of driver ants. There was no response. Apparently, the ants did not perceive the garden as a source of prey. Their assault began only after I had crumbled the fragile material to expose the termite workers inside. Then the driver ants infiltrated every crevice and pulled out dozens of the buttery-soft termites.
During their second night of gathering termite booty, I could hardly get close to the trail, which had become completely walled over by a bristling envelope of guards. By knocking the guards away, I succeeded in getting a view of the ants below, many of which were now carrying termite corpses away from the ant nest. They were transporting their own brood as well, slung under their bodies in the same way they carried food. The raid trail had become a migration route, and it was clear why. Caspar and I held our noses against the stench arising from the nest: under our feet, the termites had begun to rot. The driver ants were abandoning ship, taking with them any salvageable meat and leaving the garbage-thieving acrobat ants to scavenge the decomposing bodies left behind.
Army ants, including driver ants, often migrate along a prior raiding route, while at the same time conducting a raid along another. Near the migration’s midway point, the queen makes her run, shielded by a retinue of workers. To see this happen requires round-the-clock diligence. I took advantage of this opportunity and lay down on my side at what I thought was a safe distance from the trail, with my headlight duct-taped to a nearby tree branch to cast a steady beam of light. Unfortunately, my days had been long ones. I recall noticing that among the migrating Dorylus rubellus ants were tiny workers I had never seen at any other time; presumably, they served as nurses. But then I fell into a dream about being a dwarf ant—only to