Two hundred million evenly spaced dirt cones covering an area the size of Great Britain in northeastern Brazil’s caatinga region were built by a single leaf-eating termite species, Syntermes dirus, over four millennia, according to research published by entomologist Stephen Martin of the University of Salford and botanist Roy Funch of the Universidade Estadual de Feira de Santana in a 2018 study in Current Biology.
Scale and Dimensions of the Brazilian Murundus
The mounds, locally known as murundus, stand about 2.5 meters high and span nine meters across at the base, with a spacing of roughly 20 meters from neighboring structures. According to reporting compiled via satellite imagery and field mapping, these earth heaps cover approximately 230,000 square kilometers. The total volume of displaced soil reaches roughly 10 cubic kilometers—an amount researchers likened to 4,000 Great Pyramids of Giza. In a Cell Press statement, Martin described the phenomenon as the most extensive bioengineering effort ever undertaken by a single insect species.
Why the Termite Mounds Survived for Millennia
Unlike identical spoil heaps created by Syntermes dirus in wetter regions like the Amazon, which get flattened by wind and rain within years, the caatinga environment preserves the structures. Rain arrives only during a brief, concentrated period, after which the thorn-scrub forest bakes. As documented by Revista Pesquisa FAPESP, soil samples extracted from the centers of 11 mounds returned radiocarbon dates ranging between 690 and 3,820 years old, meaning some dirt was moved while ancient Egyptians were constructing pyramids.
Did you know?
The mound field covers close to 88,000 square miles—roughly the footprint of Minnesota—and creates a faint, dimpled texture visible from satellite imagery.
Comparing Brazil’s Murundus to South Africa’s Heuweltjies
While the Brazilian mounds represent waste piles from subterranean feeding tunnels rather than active nests, older subterranean structures exist elsewhere. Soil scientist Michele Francis of Stellenbosch University led a research group that radiocarbon-dated termite mounds known as heuweltjies along the Buffels River in Namaqualand, South Africa. As announced by the university in 2024, carbonate samples from these South African mounds—built by a different species and still actively occupied—dated back as far as 34,000 years, eclipsing the age of the Brazilian site.
Unresolved Mysteries and Environmental Risks
Despite extensive mapping and the use of fibre-optic cameras fed down the central shafts of the murundus by Martin and Funch, researchers have yet to locate a royal chamber, a queen, or a map of the underlying network. Funch told Popular Science that excavating mounds with a backhoe would be necessary for a proper expedition. Meanwhile, agricultural land clearing for cattle pasture poses a threat to the caatinga. MapBiomas estimates that between 18 and 54 percent of surviving native vegetation is degraded, risking wider desertification in a landscape protected only by naturally acidic, nutrient-poor soil.
Frequently Asked Questions
What are the murundus in Brazil made of?
According to Martin and Funch’s research, the mounds are amorphous lumps of soil hauled up and dumped by the termite species Syntermes dirus as a byproduct of carving out vast underground feeding tunnels.
Are termites still living inside the Brazilian cones?
No. When cut open, the cones are sealed at the top with no ventilation, chambers, or resident insects, functioning strictly as waste heaps or tailings from belowground activity.
How old are the oldest termite mounds discovered?
While the Brazilian murundus date back up to 3,820 years, Stellenbosch University announced in 2024 that occupied heuweltjies in Namaqualand, South Africa, contain carbonates dating back 34,000 years.
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