A “Band of Brothers” species of warring ant has been observed rescuing injured comrades from the field of battle, carrying them to safety, and tending their wounds.
The extraordinary behaviour of African Matabele ants is thought to be unique in the animal kingdom.
It results in a dramatic reduction in casualty rates as the ants carry out high-risk raids on termite foraging sites.
Scientists found that help from the “medics” cut the death rate of injured ants from 80% to just 10%.
The ants even displayed a form of heroism as badly injured insects too far gone to save refused to co-operate with their helpers.
German researchers made the discovery after studying violent clashes between the ants and termites in Comoe National Park, Cote d’Ivoire.
The team led by Dr Erik Frank, from Julius-Maximilians University in Wurzburg, wrote in the journal Proceedings of the Royal Society B: “Heavily injured ants (loss of five extremities) were not rescued or treated; this was regulated not by the helper but by the unresponsiveness of the injured ant ..
“We show organised social wound treatment in insects through a multifaceted help system focused on injured individuals. This was not only limited to selective rescuing of lightly injured individuals by carrying them back (thus reducing predation risk), but, moreover, included a differentiated treatment inside the nest.”
Marching in long files of 200 to 600 insects, colonies of Matabele ants were found to launch their termite raids two to four times per day.
Numerous worker termites were killed and hauled back to the ants’ nests, to be eaten. But often the ants met strong resistance as the termites used their powerful jaws to slice through enemy limbs.
Injured ants secreted a chemical pheromone scent signal that compelled other soldiers to come to their aid.
Casualties were carried back to the nest, where their open wounds were “treated” by intensive licking, often for several minutes, the scientists learned.
Dr Frank said: “We suppose that they do this to clean the wounds and maybe even apply antimicrobial substances with their saliva to reduce the risk of bacterial or fungal infection.”
While slightly injured ants kept still and even pulled in their remaining limbs to facilitate being carried, their badly wounded comrades struggled and lashed out wildly.
“They simply don’t cooperate with the helpers and are left behind as a result,” Dr Frank added.