by Shaun Doyle

Termites can be real pests. They chew through the wood in our homes, and can eat a home inside out, making it completely unlivable. The irony is that termites can build not just houses, but veritable cities of their own. These ‘cities’ house, feed and protect them with great efficiency, and with very little wastage. Termite mounds can be as high as 9 m (30 feet). If this were scaled up to human terms, that would be like building a structure 2 km (1 ¼ miles) high! And not just any structure either: it would involve a nursery, farms, and a massive ventilation network to keep the building air-conditioned.

Temperature control

Termite mounds can be found in climates with severe temperature extremes, where daily temperature variation can be up to 30°C (54°F1). Termites have a number of ways to deal with such extreme temperature differences.

In dry climates, termites follow the same principle as the people of Coober Pedy in outback Australia, who mostly live underground. The termites bury their nest beneath the mound, well below ground level. Despite the heat fluctuations on the surface, the soil acts as an enormous heat sink. Due to this large ‘thermal mass’ of the surrounding soil, the temperature barely changes throughout the day.

In addition, the spires of their mounds are constructed to point towards the average position of the sun at midday. This minimizes the area exposed to the sun’s rays in the hottest part of the day, which helps to keep daytime mound temperatures constant.

Living underground is, however, not an option for some termites, such as the ‘magnetic termites’ of northern Australia. They live in wetter climates, so an underground nest would be flooded in the wet season.2 To avoid this, they live inside their mounds above the ground surface. But this brings the colony much closer to daytime temperature extremes, especially in the dry season.

So these termites orient the broad faces of their mounds east-west to help control nest temperature.3  The colony also stays near the eastern face of the mound during the day because it affords the most constant temperature….


Continue Reading on