How ants find their way in the desert

Feb. 17 (UPI) -- How do animals navigate featureless landscapes like a desert? To find out, researchers decided to study one of the most efficient navigators in the natural world, the desert ant.

All desert ants belong to the Cataglyphis genus. There are dozens of Cataglyphis species. Researchers at the University of Freiburg in Germany tested two desert ant species on a rotational treadmill designed to replicate their journeys to and from the nests on the desert salt pans.

"This gives us almost unlimited possibilities to test the mechanisms and neural basis of our model animal's spatial orientation and navigation -- in the laboratory," researcher Matthias Wittlinger said in a news release. "We can place the ants in a virtual world and incorporate certain changes into it to see how they react."

The treadmill is similar to a hamster wheel, allowing an ant specimen to walk using its normal gait. The bearing-like designs allows the ant to seamlessly change directions. Optical sensors record the ant's speed and direction.

Scientists had specimens walk several feet from their nest, both in the lab and in the natural desert setting, before placing the ant on the treadmill. Their data showed the ant takes the most direct route back to its nest using information stored on its outward foraging trip.

When the ant comes within a short distance of its nest, its movements become less direct as the ant shifts into a more meandering mode of navigation, searching for the exact location of the nest.

The longer, more direct portion of the return journey is faster; the ant slows its gait when it switches into search mode close to home base.

Lab tests and field observations confirm previous studies, which suggest ants -- especially desert ants -- boast a sophisticated internal navigation system. Research suggests desert ants count their steps on their outward journeys, and use a combination of solar positions and an internal clock to track their shifting directional orientation.

Scientists published their research in the Journal of Experimental Biology.