It’s not aliens either. But it is as close as it can get.

Furthermore, the amount of soil excavated to build the structures averages over 10 cubic kilometers, which is equivalent to just about 4,000 great pyramids of Giza.

The mysterious mounds were not built by human hands, but rather by termites.

According to a study published in ‘Current Biology‘, the vast array of regular spaced termite mounds are still inhabited to this day.

The mounds are so large they are visible from Google Earth.

Scientists say they are not nests. These structures are the result of “the insects’ slow and steady excavation of a network of interconnected underground tunnels,” explain researchers.

According to researchers, the termite’s activities over periods of thousands of years has resulted in massive quantities of soil being excavated and deposited in approximately 200 million cone-shaped mounds. The mounds average around 2.5 meters in height and as much as 9 meters across.

“These mounds were formed by a single termite species that excavated a massive network of tunnels to allow them to access dead leaves to eat safely and directly from the forest floor,” says Stephen Martin of the University of Salford in the UK.

Image: Sketch showing the mound structure and network of major tunnels (solid lines) and smaller vertical foraging tunnels (dashed lines). Credit: Current Biology.

“The amount of soil excavated is over 10 cubic kilometers, equivalent to 4,000 great pyramids of Giza, and represents one of the biggest structures built by a single insect species.”

“This is apparently the world’s most extensive bioengineering effort by a single insect species,” adds Roy Funch of Universidade Estadual de Feira de Santana in Brazil. “Perhaps most exciting of all–the mounds are extremely old–up to 4,000 years, similar to the ages of the pyramids.”

Despite being one of the largest structures on the Earth, the massive mounds remain well hidden from view, tucked away in the semiarid, thorny-scrub caatinga forests unique to northeastern Brazil.

Soil samples analysis taken by experts from the center of the mounds indicate that they were filled 690 to 3,820 years ago.

The mound pattern created by the termites is thought to have come into existence through self-organizational processes.

The mounds are interconnected by vast tunnels which allowed termites to minimize their travel time from any location in the colony to the nearest waste mound, giving them access to a sporadic food supply.

“It’s incredible that, in this day and age, you can find an ‘unknown’ biological wonder of this sheer size and age still existing, with the occupants still present,” experts concluded.

Curiously, the queen’s chamber has never been found.