How a classic computer game is giving native ants a fighting chance against invasive species

A computer game once given away in kids’ cereal boxes is helping Australia eradicate an invasive ant species.

Australia’s national science agency CSIRO and the University of Western Australia have used Age of Empires to simulate ant warfare, to figure out how to help native ant species fight their invasive counterparts.

“Ants are one of the few groups of animal species in which warfare resembles human warfare, in terms of scale and mortality,” researcher Samuel Lymbery said.

Using the game, the research team built armies and battlegrounds of different sizes and shapes and watched them fight, then mapped the results.

“We formed small groups of strong soldiers, and we opposed them to increasingly larger groups of weaker soldiers,” Dr Lymbery said. 

And while it may seem fun to play a computer game for work, Dr Lymbery said it wasn’t as entertaining as you’d think. 

“What you want to do is set up exactly the same scenario over and over again, run it in a very repetitive fashion, and not interfere too much,” he said.

“This is probably the most boring way to play a video game.” 

Native versus invasive 

For the study, the team looked specifically at the large, native Australian meat ants and the small, non-native Argentine ants.

The armies created in the game behaved in a simple, predicable and quantifiable way, allowing mathematical models of warfare to emerge.

The researchers then conducted laboratory experiments with ants and compared the models to the “messy” real-world examples, using actual animals that behaved unpredictably.

“It allows you to identify points of commonality and difference between the simple and more complex systems,” Dr Lymbery said. 

They found small armies of strong soldiers did better in complex terrain-based battlefields and large armies of weaker soldiers did better in simple open battlefields.

Putting this into a real-world context — for ants, a simple battlefield would be a footpath or urban park, and a complex battlefield would be a bushland strip with undergrowth, small bushes,and woody debris. 

Dr Lymbery said his work could help develop new approaches to habitat management, like adding undergrowth or more environmental complexity back into urbanised environments, to tip the competitive balance back in favour of native ants.

Invasive ants in Australia  

Across the country, 50 different species of invasive ants have established themselves, including electric ants, fire ants and yellow crazy ants.

Invasive Species Council principal policy analyst Carol Booth said in Australia, ants were “one of the worst invasive species problems”.

Hundreds of millions of dollars are spent nationally to eradicate the pests.

But Dr Booth said they were incredibly difficult to get rid of. 

“They can form these vast super colonies with multiple queens and many interconnected nests, which allows them to achieve these really high densities, over vast areas,” she said. 

As well as out-competing native ant species, invasive ants are able to prey on native animals and can cause extensive damage to agricultural systems by damaging infrastructure and ruining crops.

Despite the challenges, Dr Booth said Australia has established itself as a world leader in invasive ant eradication. 

“The capacity we now have to eradicate ant populations — that will only continue to improve,” she said. 

But she said improving biosecurity measures to stop them arriving was still important, as well as investing in research to better understand ant invasions and develop new methods for detecting and controlling them.

Dr Lymbery’s research only involves one type of invasive species, so the results cannot be extrapolated to other species.

But he is hoping to expand his work further. 

“It opens up a potential avenue that we should explore for management across more species,” he said.