Termite mounds are among the largest structures built by any nonhuman animal. They reach as high as thirty feet, which, proportional to the insects’ tiny size, is the equivalent of our building something twice as tall as the 2,722-foot Burj Khalifa, in Dubai. The mounds are also fantastically beautiful, Gaudíesque structures, with rippling, soaring towers, in browns and oranges and reds. The interior of a termite mound is an intricate structure of interweaving tunnels and passageways, radiating chambers, galleries, archways, and spiral staircases. To build a mound, termites move vast quantities of mud and water; in the course of a year, eleven pounds of termites can move about three hundred and sixty-four pounds of dirt (in the form of mud balls) and thirty-three hundred pounds of water (which they suck into their bodies). The point of all this construction is not to have a place to dwell—the colony lives in a nest a metre or two below the mound—but to be able to breathe. A termite colony, which may contain a million bugs, has about the same metabolic rate as a nine-hundred-pound cow, and, like cows (and humans), termites breathe in oxygen and expel carbon dioxide. The mound acts as a lung for the colony, managing the exchange of gases, leveraging small changes in wind speed to inhale and exhale. Also like lungs, a termite mound has a role as a secondary diffusion system, which carries oxygen to and carbon dioxide away from the far reaches of the underground termite nest.