Warrior and nurse ants

Matabele ant cleaning the wound of an injured fellow ant (green) © Erik Frank
Matabele ant cleaning the wound of an injured fellow ant (green) © Erik Frank

Matabele ants are able to detect and treat infected wounds in their fellow ants. The work carried out at the University of Lausanne’s Department of Ecology and Evolution on this African species is the subject of a publication in "Nature Communications" and a documentary.

Pugnacious Matabele ants (Megaponera analis) are known for their spectacular raids on termites, on which they feed. But they’re not the only ones. This species, which is widespread in the southern Sahara, also provides the only known example (apart from humans) of a living creature using ’medicine’ to save the life of a fellow creature.

In 2017, Erik Frank, a former postdoctoral fellow in the Department of Ecology and Evolution at the University of Lausanne, now at the University of Würzburg (Germany), discovered that these hymenopterans came to the aid of their wounded in battle. Like real stretcher-bearers, the worker beetles would repatriate crippled soldiers (almost a quarter of them leave the battle with one or two legs missing) to the nest, then lick their wounds to disinfect them.

In a new study published on December 29, 2023 in Nature Communications, Erik Frank shows this time that Matabele ants are able to determine when wounds are infected, and treat them accordingly. By applying various antimicrobial compounds and proteins secreted by their metapleural gland to wounds, workers reduce the mortality of infected individuals by 90%.

But how do they determine the state of health of their injured comrades? Chemical analyses have shown that wound infection is associated with specific changes in the profile of cuticular hydrocarbons, probably enabling conspecifics to diagnose the infectious state of the wounded and apply the appropriate antimicrobial treatment", says Erik Frank, first author of a study led by Laurent Keller, former professor at the University of Lausanne.

In 2020, he signed an autobiography ( read the news ) in which he recounts his experience of living in the Comoé National Park in northeast Côte d’Ivoire, and the scientific work he carried out there. Entitled Combattre, sauver, soigner. Une histoire de fourmis , the book is now also available in pocket format (published by CNRS).

The biologist’s discoveries about these astonishing creatures, at once warriors, saviors and caretakers, are also featured in a recent documentary produced by Steven Spielberg and narrated by Morgan Freeman.

by Mélanie Affentranger