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Researchers discovered that desert ants measure distance by counting steps, a finding made possible by equipping them with stilts. Matthias WittlingerAnts walking on stilts might sound like a circus act, but for scientists, it’s a groundbreaking method to unravel a fascinating mystery.
Picture a desert ant venturing out of its nest, searching for food across the ever-changing sands under scorching heat. After finding food, it takes a direct route back to the nest. But how does it navigate so precisely?
“Returning to the nest is incredibly challenging,” explains Nick Bos, an ant researcher at the University of Helsinki. “The shifting sands erase any chemical trails left by the ants, making chemical navigation impossible.”
Adding to the challenge, desert ants lack landmarks to guide them back. “Wood ants navigate using the forest canopy, observing how light filters through, but this isn’t an option in the desert,” explains Bos.
To understand how ants locate their nests, researchers equipped them with stilts made from pig-hair bristles.
Matthias WittlingerDespite lacking traditional navigational aids, desert ants possess an extraordinary ability to chart the most direct path back to their nest, regardless of how far or winding their journey. “It’s remarkable, especially given the chaotic and twisting nature of their outbound paths,” says Bos.
In a 2006 experiment, a team of scientists from the University of Ulm in Germany and the University of Zurich in Switzerland tested ants by intercepting Saharan desert ants (Cataglyphis fortis) on their way home. They attached tiny stilts made from stiff pig hair to the ants’ legs and observed their return journey. Consistently, the ants overshot their nests due to their elongated legs.
Without tree shadows to gauge distance, desert ants rely on counting their steps.
ScienceResearchers hypothesized that the ants, with their artificially lengthened legs due to stilts, covered more ground with the same number of steps. This led to the question: Are ants effectively “counting” their strides?
To verify this idea, scientists shortened the legs of some desert ants by partial amputation, causing them to take smaller steps. When these ants attempted to return to their nests, they stopped prematurely, believing they had arrived, even though they were still far from their destination.
The study concluded that desert ants possess an innate step-counting mechanism, functioning like a natural odometer. While they aren’t consciously counting steps, this internal system helps them estimate the distance needed to return home.
Saharan desert ants can survive internal temperatures soaring up to 131 degrees F (55 degrees C), a level of heat that would be fatal for most other creatures.
