Heroic altruistic ants die alone to save colony

It's not just action movie heroes who face death alone to save their people. Scientists have found that ants act in a similarly altruistic fashion when stricken with disease.

They discovered that when ants of the species Temnothorax unifasciatus get sick, they abandon their nest, walking far away from their relatives to die alone.

They perform this act of heroism to prevent the illness that is killing them from spreading to the colony.

The discovery by Professor Jurgen Heinze and PhD student Bartosz Walter is the first time that such behaviour has been shown in ants or any other social insect.

During the study, researchers exposed a colony of Temnothorax unifasciatus ants reared in their laboratory to the spores of a lethal parasitic fungus called Metarhizium anisopliae.

Most of the workers who died from the fungal infection permanently left the nest hours or days before death, and died in a foraging area far from their nest mates.

"Our study suggests that infected ants at least in some species walk away from a colony and die alone, rather than risk infecting others," the BBC quoted Prof Heinze as saying.

The study has been published in Current Biology.