No bug left behind: Ants aid battle-wounded comrades, study says

In scenes reminiscent of an epic war movie, researchers have recorded footage of termite-eating ants coming to the rescue of their battle-wounded nest-mates.

African Matabele ants (Megaponera analis), which are widespread south of the Sahara desert, set out to hunt several times a day. They travel in long lines, raiding termite nests, getting into pitched battles with ‘soldier’ termites and carrying prey back to their nest.

It’s a risky business for the ants - the soldier termites are equipped with powerful jaws which can kill or maim, sometimes costing the ants numerous limbs during their sparring.

However, a new study has found that the ants have developed a special rescue system hitherto unknown in insects. The wounded ants emit pheromones to alert warrior ‘Major’ ants which carry out the rescue operations, fighting off spiders and other predators to save members of their colony.

The injured insect is then carried back to the nest to recuperate. Ants that lose one or two of their six legs are able to adapt their movement, and can even regain running speeds similar to a healthy ant within an astonishing 24 hours.

A German research team from the University of Würzburg discovered the rescue behavior and published a paper on it in the journal ‘Science Advances’. The study is the first evidence of ants rescuing nest-mates even though they are not in imminent danger - an unexpected finding, the researchers say, as individuals are usually of little value among social insects.

"We have observed helping behavior vis-à-vis injured animals for the first time in invertebrates,"said Erik Frank, one of the researchers.

"This is not an altruistic behavior," Frank explained to Reuters. "The ants do not help the injured out of the goodness of their hearts. There is a clear benefit for the colony: these injured ants are able to participate again in future raids and remain a functioning member of the colony."

Nearly all the rescued ants participated in later raids, sometimes less than an hour after being injured.