No. 74: Mar-Apr 1991
Few animals besides man have significantly affected our planet's geology. To be sure, corals built the Great Barrier Reef and beavers left their mark on the hydrology of parts of Canada and the U.S.; but termites!? It seems that in southern Africa this industrious insect is responsible for enormous striped patterns of ridges and vegetation bands. These amazingly regular patterns are caused by alternating low ridges and gullies. The ridges are about 2 meters high, up to a kilometer long, and separated by about 50 meters.
The ridges themselves are closely spaced termite mounds. Just why the termites choose to build their mounds in long rows is an unanswered question. And how do the termites maintain strict parallelism, especially since they are blind? How could termites in one mound know how their neighbors in the nearest ridge, 50 meters away, are building their mounds? Anyway, the ridges help channel the flow of water and thus the growth of vegetation, giving immense swathes of country a corrugated appearance. (Sattaur, Omar; "Termites Change the Face of Africa," New Scientist, p. 27, January 26, 1991.)
Comment. In Australia, the so-called "magnetic" termites build their slab-like mounds so as to minimize the amount of sun-generated heat.