Anti-social behaviour was revealed by DNA fingerprinting of ant colonies

But new research suggests that their colonies are actually hotbeds of devious, selfish and corrupt behaviour.

And it is the royal family - or male ants carrying a so-called "royal" gene - that are largely to blame.

Scientists have discovered that some males pass the gene on selectively, to ensure that their offspring become reproductive queens, not mere workers.

The research, published in the Proceedings of the National Academy of Sciences, used DNA fingerprinting on five colonies of leaf-cutting ants.

The rarity of the royal lines is actually an evolutionary strategy by the cheats, to escape suppression by the altruistic masses that they exploit

Dr Bill Hughes, Leeds University

This revealed that a larva's chances of becoming queen depended largely on who its father was.

Previously scientists were adamant that the species was a model of democracy and social co-operation.

It had been thought that nurture was the driving force in selecting royalty - some larvae were fed certain foods to prompt their development into queens.

But now it seems those who have been passed the royal gene have an unfair advantage over the rest.

Dr Bill Hughes, from the University of Leeds, who led the research, said: "The core principle of social societies is they should be egalitarian. We've found this isn't always the case, and that some of the males are cheating. There is a genetic influence on royalty."

Genes will help decide whether these ants are royals, or workers

The royal genetic lines are rare in each colony, leading the scientists to think that the ants cunningly spread their sperm around different colonies, so that the unfair advantage to their offspring is not spotted.

If too many larvae became queens, the imbalance could be noticed by the "commoner" worker ants, who might then turn on their leaders.

"When studying social insects like ants and bees," said Dr Hughes, "it's often the co-operative aspect of their society that first stands out."

"However, when you look more deeply, you can see there is conflict and cheating - and obviously human society is also a prime example of this. It was thought ants were an exception, but our genetic analysis has shown that their society is also rife with corruption - and it's royal corruption at that."