A gruesome experiment with ants proves they have built-in odometers

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It's easy to see how ants get around when they're in a long line – just follow the ant in front of them. But how do ants find their way back to nest when they're on their own? A creepy experiment provides clues.

Ants are tiny, have brains that are even tinier, and have eyes that are only a couple of millimeters off of the ground, and yet every day they trek into foreign territory, bravely searching for food, looking for better places to nest, and getting into everyone on earth's friggin' kitchen in the winter. But they can't just explore. They have to find their way back. Scientists have figured out at least one way ants manage to get back home after their long voyages. Tiny ant brains contain odometers capable of counting the number of steps from the nest to any target.


Scientists found this out by placing various items of interest around ant nests. When exploring ants came out to find them the scientists picked up the ants, and changed the length of their legs. Sometimes the scientists added tiny stilts to the ant legs, which had to have been a very fun assignment for an engineer and a frustrating task for a lab assistant. At other times, the scientists partially amputated the legs of the ant, which sounds like a mini-version of the Saw franchise. Whether they shortened or lengthened the legs of the ant, they always put the ants back in the discovery spot. They then watched the newly-mutilated ant go home. If the ants' legs were lengthened, they overshot the nest. If the legs were, to put it euphemistically, shortened, they undershot it. However, if the ants were, to once again put it euphemistically, 'modified' before they set out on their journey, they made their way to the object and back with no trouble. To get around, ants literally count their steps.

This experiment may turn a few stomach, even though it deals with awful little bugs. It also makes an interesting ethical thought experiment. Which version of the experiment would you rather participate in; the long, frustrating slog of trying to attach stilts to ant legs, or the short gruesome task of chopping off ant legs left right and center?


Via Pubmed.