African Matabele ants observed carrying injured comrades from the battlefield

Scientists have observed a species of ant rescuing injured comrades from the battlefield, carrying them to safety, and tending their wounds.

The behaviour of African Matabele ants is thought to be unique in the animal kingdom.

The actions of the ants result in a reduction in casualty rates as they 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.

"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," said Dr Erik Frank, from Julius-Maximilians University in Wurzburg.

"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."

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.

"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," Dr Frank said.

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.