Tiny Architects

At sunset they look like squat people dotted across the plain. Here, 450 km below Karratha, the invisible population of the bush busies itself in mounds rising a meter or so above the spinifex scrub. Three hundred of the world’s 3,000 termite species live in Australia. Most are rarely seen, but their monuments are everywhere on display.

Heading north, the structures seem to grow taller, until they turn into massive domes and spires. The largest mounds hold upward of a million insects working in blind harmony. Mounds can reach 7 m high and 12 m around the base, and may have taken a century or more of painstaking construction. The termites mix a drop of saliva with soil, plant matter and excrement and deposit it like a tiny brick; somehow, in the darkness, each knows where to place its contribution to form the maze of tunnels and chambers that harden like concrete.

Further north, the magnetic termites of the Northern Territory align their tall, narrow nests perfectly north to south. The thin-skinned insects are highly sensitive to temperature, and the orientation of the gravestone mounds allows the Territory sun to pass overhead without overheating the inhabitants. Elsewhere, termites burrow underground to escape the heat or open and close vents in an air-conditioning system, but during the big wet of the Top End that’s not an option.

To the touch, the ocher walls are smooth and warm; no creatures are visible, so you poke a stick into the mound. Seconds later the repairman arrives and starts plugging the hole. Poke again, and another laborer turns up. Another hole, another worker. And there are a hundred thousand more waiting to play. It’s a fun game, but you’ll tire of it before they do.