Millions of miles of tunnels go largely unnoticed under the feet of farmers in the northeastern part of Brazil. About four inches wide, these smooth and twisting passes penetrate at least five meters in the country, most likely more. Given that their architects carefully carried out the underground grain engineering grain, they unwittingly made major changes over the earth.
After four thousand years, the inhabitants of the overworld have finally become interested. Countless terrain hills in the northeastern part of Brazil, where they are known as ants, but only recently came attention of entomologists. According to the new theory described on Monday in Current Biology, insect-sized buttons have built these monuments to keep them alive, but as remains for their underground excavations. The scale of their activity cements the reputation of critters as ecosystem engineers at the same level as any other type of planet.
"It's incredible to think that long tertients with a centimeter did it," says Roy Funch, botanist at the Brazilian University Estadual de Feira de Santana, and the driving force behind the study of the graves. "They are everywhere, not just 10 or 20, but literally millions of them."
The scope of this phenomenon defies visualization. Each structure looks like a cone of ice cream from a transitional part that reaches eight feet above the ground and covers about 30 feet at its base. Arranged in a striking honeycomb pattern, about 200 million euros ants stretches across nearly 90,000 square miles of Brazilian bushes – a similar size similar to the UK. All told, if you take that dirt, you will need about 4,000 large pyramids in Giza to keep it, or a cube box of 2.3 miles per side.
Perhaps more mysterious than the degree of graves is their constant distance. Funs initially assumed that each cone is a colony that defends its grass from endangering rivals, but when given a chance to duel most of its neighbors, they do not take the bait, he discovered, suggesting that local clusters tend to belong to a " family "of friendly termites. They will fight with outsiders, but from all over the zone must contain many different termite groups.
Instead, the secret of positioning the masses lies in their function – or lack thereof. Some types of termites live in their constructions, while others use them for ventilation, but ants are ordinary piles of dirt, sealed in the outside world. Like mini-volcanoes in the structure, they have only one central column that the termites climb before sending dirt that descends along the outer wall. Instead of serving as homes or functional accessories, the team suggests that they are just a heap of ruins.
"It's the difference between a high-rise building and a slag," says Funch.
Life like Syntermes dirus it is not easy. Their broken bodies are dried quickly under the Brazilian sun, so they do not leave their underground fibers during the day. Of the dozens of workers each night appear to feed on leaves, but only under the protection of soldiers with terrible, clicking mandibles – locals call them bate-cabeças, or the head snappers.
With the overworld world as a hostile place, the termites aim to spend their entire time in their spatial and continuously expanded tunneling network, so that with evenly distributed removal cavities helps ensure that they are never too far from the place to remove some dirt.
Scott Turner, a SUNY physiologist who studies termites in southern Africa, is not surprised that these Brazilian termites can reshape the world to suit their needs. "It's one of the undervalued stories of the biology of social insects, only with the simple act of moving the soil, these things can make incredible endeavors to modify their environment," he says. He thinks it would be even more interesting to learn how many dirt the insects move, which can be measured by incorporating styrofoam grains into the soil and seeing how fast the termites clean. This will help to show how erosion could level this rise in levees.
Funck was the first to be interested in the graves in the early 80's after completing the peace corps tour. They were a famous feature of the local landscape, but since they were buried under a 20-meter layer of interlocking spiked shrubs and trees known as caatingano one took the time or risked studying the ridges in depth. In the end, local activity made them more accessible. "If farmers do not open part of the path for grazing, no one has seen these embankments," Funch says.
However, another 30 years went before FUNCH to get the chance to take over the project on its own. A botanist with training, he applied to postdoctoral study for caatinga vegetation as an excuse for digging in the graves. His recent results are upgraded after the announcement of landmine releases in 2015, as well as a survey of satellite images by French researchers in 2017, documenting their extent.
Despite the fact that scientists have lived largely ignorant of these cones, they have been around for a long time. Fanch dated 11 samples from northeastern Brazil with a relatively new technique that uses cosmic rays as a natural clock. Like particles of deep space slam in crystals inside the graves, electrons are ejected and stuck in new locations with predictable rates. When the researchers heat or illuminate the crystals in a laboratory, the electrons return to their original locations, giving a pale flash. Based on the number of these rockets, the team found that the mounted samples ranged from about 700 to nearly 4,000 years ago. In future studies, Fanch hopes to examine more mounds to get a more precise range, and also different layers within a mound, which will give an idea of how long the embankment should be formed.
His team has more dramatic plans. He and co-author Stephen Martin, an entomologist at the University of Salford in England, pushed the optical fiber cams down the tunnel as far as they could go, but twists and turns prevented them from finding the queen's chamber. The next step, says Funch, is "to return a few muds in oblivion" and fill a full expedition in this unexplored world, how to locate the queen, and understand the basic structure of the tunnel network. "We do not know anything about architecture or geography," he says. "We just scratched the surface".