Climate control and resource management by the passive architecture of a termite mound

A tropical termite nest represents a massive superorganism of insects in varying developmental stage and gardens of symbiotic fungus. Its climatic needs, for thermoregulation and ventilation, and moisture budget are largely mediated by the gigantic mound structures that termites build above their nests, through which energy and mass fluxes must pass. Previous work has documented how mound shape, in response to daily thermal oscillations, creates internal temperature gradients which drive flow sufficient to exchange respiratory gases. We now present evidence that the mound's passive structure along with its composition of adsorbent, clay-rich material, harnesses the same external thermal forcing to induce periodic condensation of water from its vapor phase, similar in design and function to recent human-engineered devices for sorbent-based atmospheric water harvesting. Insight from this evolved solution may inform design of soil-based systems that leverage geometry, rather than exotic chemistry, for performance.