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, published in Current Biology, is the first time that such behaviour has been shown in ants or any other social insect.

Professor Jurgen Heinze and PhD student Bartosz Walter decided to investigate the ants’ behaviour after becoming interested in anecdotal reports of dying individuals deserting their families.

The workers left the nest voluntarily and were not carried away. Such behaviour has been reported in dogs, cats, elephants and even people. But because it happens occasionally, it cannot be quantifiably studied. So Prof Heinze decided to set up an experiment to study the phenomenon in ants, which he also noticed would occasionally leave the colony for no apparent reason.