These ants build tall nest hills to help show the way home
Some ants have figured out how to keep from getting lost: Build taller anthills. Desert ants that live in the hot, flat salt pans of Tunisia spend their days looking for food. Successful grocery runs can take the insects as far as 1.1 kilometers from their nests. So some of these ants build towering hills over their nests that serve as a landmark to guide the way home, researchers report in the July 10 Current Biology. “I am surprised and fascinated that ants have visual acuity at the distances implied in this work,” says ecologist Judith Bronstein of the University of Arizona in Tucson who wasn’t involved in the new study. It “also implies that ants regularly assess the complexity of their local habitat and change their decisions based on what they conclude about it.” Desert ants (Cataglyphis spp.) use a navigation system called path integration, relying on the sun’s position and counting...