The world’s oldest termite colony holds secrets – to the past and future

The discovery of a 34,000-year-old mound in South Africa sheds light on the insects’ role in combating climate change

On a cloudless September morning in Buffelsrivier, a desolate corner of Namaqualand some 530km (329 miles) north of Cape Town, Stellenbosch University soil scientists Cathy Clarke and Michele Francis watch as a giant Volvo excavator tears into the dry ochre earth. Over the next five hours the excavator works hard to dig a trench, 60m (197 feet) long and 3m (10 feet) deep, through the heart of a giant, low-slung mound known locally as a heuweltjie or “little hill”. It’s all part of a university project to understand why the groundwater in the area is so salty.

Once the digger has returned to the nearby town of Springbok, population 12,790, Clarke, Francis, and a bevvy of grad students begin to explore the trench. They start at its extremities, what Francis describes as the “boring bits”, feeling the soil and looking for signs of life. As they move inwards, they start to notice small conglomerations of bewildered southern harvester termites (Microhodotermes viator) furiously trying to repair the damage done to their home.

At the centre of the trench, two metres (6.6 feet) below ground level, they encounter “this huge nest that looks like a giant alien”, Francis tells Al Jazeera. Clarke nods in agreement: “The moment I saw it I knew we were witnessing something special. It was just so obviously ancient … And alive.”

Once they’d taken some time to simply marvel at the work achieved by these 1cm (0.4 inch)-long creatures, they moved on to the business at hand: taking soil samples. “I delegated the task to a young male student with a pickaxe,” laughs Clarke. “But he couldn’t get the steel blade to penetrate the sides of the trench.” The ground was so hard, according to John Midgley – an entomologist at the KwaZulu-Natal Museum who was not involved in the project – because it was part of an “ancient mound” created by termites over thousands of years. Eventually, after lots of huffing and puffing, the grad student was able to obtain a sample the size of a soccer ball, which was sent for testing.

This kind of challenge is all in a day’s work for soil scientists, says Clarke, who describes her discipline as “a fun mix of everything from bucket science to high precision X-ray techniques”.