Compass Termite

Amitermes meridionalis is one of three closely related compass-termite species endemic to northern Australia (Northern Territory and northern Queensland). The species is famous for the geometric architecture of its mounds: each colony's mound is wedge-shaped, with the long axis aligned almost perfectly north-south. The broad faces of the wedge point east and west; the thin edges point north and south. This orientation minimizes solar heating during the hottest part of the day (when the sun is overhead, only the thin north-south edges are exposed) while maximizing morning and evening sun (when the broad east and west faces catch slanting light). The result: interior temperatures stay within a workable range despite outside air temperatures reaching 40°C. The termites use Earth's magnetic field as the reference for orientation; experimental displacement of magnetic fields around developing mounds causes them to rotate. The species also sometimes builds 'cathedral' shaped mounds when the magnetic field is disrupted by local iron-ore deposits. Compass termites are wholly subterranean foragers, feeding on dead wood and grass.