Original URL: http://www.theregister.co.uk/2013/04/19/ant_careers_report/

Ants have careers; you don't want them

Jury out on whether as crushing as rat race, but it's close...

By Jack Clark

Posted in Science, 19th April 2013 21:17 GMT

Ants don't have a career ladder, they have a career hole, and only the wiliest of the insects can avoid falling down it according to the latest research.

A particular genus of carpenter ants (Camponotus fellah) exist in a complex social structure, where their first jobs see them caring for the queen and her offspring, and as the ants age many of them wind up working at more and more of a distance from the big cheese, according to an academic paper released this week.

The discovery was made by biologists at the University of Lausanne in Switzerland, who painstakingly tooled up around 1,000 ants across six colonies with sensors that let the researchers observe their every move over the course of 41 days. This generated a vast dataset containing 2,433,250,580 individual ant positions and 9,363,100 social interactions.

Nurse, forager, or cleaner?

After crunching this information the researchers discovered that the career path of the average ant typically saw it progress from being a "nurse" to a "cleaner" and finally to a "forager".

"Workers exhibited a preferred behavioral trajectory moving from nursing to cleaning to foraging as they age," the researchers wrote.

Nurses are typically young, and spend their time caring for the grand madam of the colony and her brood. Foragers spend a lot of time hunting for food and bringing it back to the nurses, and the cleaners, well, their role is characterized as having "a significantly higher propensity to visit the rubbish pile."

And you thought the rat race was bad?

And you thought the rat race was bad?

Some of the ants could escape their fate, with the researchers finding some nurses that were older than the average worker age. Other ants found themselves going straight to the rubbish pile, with the researchers detecting some cleaners who were younger than the average.

"Age-related behavioral maturation is a slow and noisy process in ants with important individual variation," they noted.

The different groups also exhibited different levels of socialization, with the nurses and foragers communicating amongst themselves twice as much as the cleaners, who were too busy cleaning or patrolling empty areas to spend much time with one another. Similar forms of social stratification have been documented in honeybees, the researchers wrote.

Nurses spend a lot of time together, cleaners - not so much

Where workers spent their time had a huge effect on the micro-societies

They also detected strong evidence for space – that is, where each worker spent the greatest amount of time – as being a key factor for the arrangement of the society (pictured).

"These results suggest that spatial structure might function as a regulating mechanism for information flow, division of labor and colony homeostasis."

The ants being experimented on existed in a brutal two-dimensional world made of of two chambers connected by a tunnel. One of the chambers existed in a state of total darkness, while the foraging chamber was exposed to daily light-dark cycles.

"The temperature, humidity, light and food supply were computer-controlled and both chambers were filmed from above with high-resolution monochrome cameras operating under infrared light," the scientists wrote.

Still, even Camponotus fellah ants that become cleaners or foragers should consider themselves lucky, for at least they're not born into a genus of carpenter ant are born with massive mandibles that, when threatened, commit suicide by rapidly evacuating their glands, causing their heads to explode and the assailant to be coated in acid. Nor do they have to brown-nose aphids to get the honeydew that gets them in the queen's good graces, as do some poor Yorkshire wood ants. ®