Readers of the book will know of my fascination with ant traffic. That’s why it was a special pleasure in Trinidad, while out walking in the forest, to run across massive streams of leaf-cutter ants. Occasionally, I would glance down to look at something on the ground, only to discern the slow movement of small macerated bits of leaf glinting as they were ferried by apparently quite strong individual ants. The leaf bits are used as compost to create a harvested fungus that sustains, and is sustained by, the ants. Exposed roots were favorite “road” surfaces, but the most astonishing thing was to look off the human trail and see the trails that the ants were emerging from — a few inches of ground cleared from the forest floor by the indefatigable six-legged march of massive ant colonies.
When I returned home, I was particularly excited to find in the mail the new book by E.O. Wilson and Bert Holldobler, “The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies.” The book, which updates and expands upon their canonical tome The Ants, is a sheer delight. The photos alone would be worth the price of admission.
In a section on the trail construction and formation of leaf-cutter ants, I was struck by this passage:
“In most cases, [the trails] are deeply engraved into the ground and conspicuous even to the most casual observer. They are retained for months or years. Even when abandoned for a time, they are commonly used again by the ants. Serving as the superhighways of the Atta colonies, they are continuously cleaned of invading vegetation and other obstacles by ‘road workers.’ The trunk route system enhances foraging speed four- to tenfold compared with that on uncleared ground.”
I rather imagine tiny ant workers, dressed in DOT orange vests, clearing debris (I’m actually not sure if there’s a special caste in the ant society that clears debris, or if everyone pitches in). This is of course a direct parallel to the whole idea of “incident management” in improving human traffic flow during peak periods; one stalled vehicle can seriously compromise the flow of a system, hence each additional minute it takes to clear means that much more congestion buildup (I’m not sure, Another parallel might be to imagine the trails as major, restricted access highways, and the uncleared ground as the smaller surface streets, with their traffic lights, double-parked cars, etc. I also learned from the book there is a species known as “driver ants.” Which I what I will know refer to my fellow vehicle operators as.
A few paragraphs on, the authors note another curious fact: The foraging area of an average colony (or “superorganism,” in the authors’ view) is 1.03 hectares, which “happens to be approximately the same ‘ecological footprint,’ or average amount of land utilized to sustain one person, in developing countries.”