The World’s Oldest Termite Mound Is 34,000 Years and Counting

Scientists recently found the planet’s longest continuously occupied termite colony in an arid region of South Africa. It dates to the time of the Neanderthals.

Last month, Michele Francis, an environmental scientist at Stellenbosch University in South Africa, relocated to central Connecticut only to discover that her new home showed signs of termite damage. When an exterminator suggested setting out traps, Dr. Francis demurred. “I wondered if I could persuade the termites to eat the trees around my house rather than the house itself,” she said. “I hold termites in high esteem.”

Her appreciation for termites stems from a project that she recently oversaw in Namaqualand, a region of desert scrubland along the west coast of South Africa and into Namibia. There, some 27 percent of the landscape is covered with low, sandy mounds that were built by the southern harvester termite, Microhodotermes viator. Inside the mounds are vast labyrinths of chambers, tunnels and nests that extend up to 11 feet underground. The locals call them heuweltjies, which means “little hills” in Afrikaans.

Three years ago, Dr. Francis and her field research team set out to find why the groundwater along the Buffels River in Namaqualand was saline. “The groundwater salinity seemed to be specifically related to the location of these heuweltjies,” she said. The investigators reasoned that radiocarbon dating could pinpoint when the minerals stored in the termite mounds had seeped into the groundwater.

The investigators were surprised to find that the heuweltjies were far older than any active termite structures known to exist. As detailed in a paper that the researchers published this spring in the journal Science of the Total Environment, one of the three mounds selected for dating has been continually occupied by termite colonies for 34,000 years. It is more than 30,000 years older than the previous record-holder, a mound in Brazil built by a different termite species.

Termites are masterful soil engineers capable of erecting cathedral-like edifices out of dirt, saliva and feces. To create and maintain their homes, they become miners, masons, scaffolders, plasterers and roofers. Working together, they don’t just build simple nests; they install air-conditioning, central heating and even security devices. In Namaqualand, the termite activity over thousands of years has resulted in the formation of a hard layer of calcite (the same mineral that limestone is made of), which protects the colonies against predators that are strong diggers, such as aardvarks.