Watch these ants rescue injured comrades from termite battles

No bug left behind is the motto of Megaponera analis, an ant species found in southern regions of Africa. Every day these hunters raid termite nests to keep their colonies fed. But the ants have chosen a dangerous prey, and tussles with large soldier termites often lead to injury—limbs and antennae are sometimes lost on the battlefield. When researchers noticed that large ants called “majors” would pick up fallen soldiers and carry the live ones back to their nests, they decided to study the fate of the injured by marking them with paint. More than 90% of hurt ants recovered to emerge from their nests and march again in future raids, the researchers report today in Science Advances. A secretion from an injured ant’s mandibles seemed to be the key to calling for help; even when perfectly healthy ants were doused in the chemical, majors came around to offer a free ride. But if no help came for an ant in need—too slow to keep up with its departing unit—that ant was almost a third more likely to get eaten by a predator or die of exhaustion on the way home. The number of ants needing rescue each day was roughly equal to the number of ants born, meaning rescues—and the distress pheromone that signals them—help colonies stay strong enough to fight another day.