In some respects, the social organisation of ants is reminiscent of human society. Their organised workforce is a caste-based community of specialists serving the needs of the queen. Soldier ants behave as if they have been trained on a military parade ground, and some species regularly wage war, fight to the death and even take ant-child slaves from conquered colonies.

Other ants cut and gather leaves to act as fodder for fungus farms, or “milk” domesticated aphids for their sugary juices. Colonies are a mix of specialist female workers, fighting soldiers, fearsome guards and fertile breeders. But each ant is programmed to know its place in society, with a selfless dedication to the task of protecting and rearing the queen’s offspring in well-tended nurseries.

The allegiance to a queen is central to ant society, even to the extent of sacrificing the reproductive potential of each sterile female worker. Indeed, this enforced infertility of worker ants has fascinated scientists trying to understand the evolution of true eusocial behaviour – a hyper -socialist version of community living.

The phrase covers the highest form of social organisation in the animal kingdom. It defines species where there is co-operative care of the brood, a mixture of overlapping generations living in the same nest or colony, and a division of labour into reproductive and non-reproductive groups who jointly defend the home nest where the young are reared.

Eusocial behaviour is a relatively new evolutionary invention and appears to be quite rare. Of the millions of species of animals that have lived during the 3.7 billion-year history of life on Earth, we only know of 20 ancestral lines that are true “eusocalists”. Fourteen of them are insects (ants, bees, wasps and termites), three are species of marine shrimp, and three are mammals – two species of naked mole rats and, arguably, humans.

The reproductive division of eusocial animals into breeding and non-breeding individuals has mystified biologists as far back as Charles Darwin. Why would some individuals give up their ability to procreate for the sake of others? In simple Darwinian terms, it doesn’t appear to make sense because a non-breeder would, by definition, not leave any offspring behind to pass on the non-breeding trait.