Imagine being unable to walk your dog along your favourite route, being forced to keep your children out of the backyard, or seeing plants and animals on your favourite hiking trail wither and die.

These are all very real possibilities if an incredibly invasive species successfully manages to escape the confines of its current south-east Queensland base.

They wreak deadly havoc, and there is currently a desperate fight to eradicate them – yet few Australians know about the threat of the red imported fire ant (RIFA).

But recent warm weather and flooding has provided perfect conditions for the pests to spread, with RIFA pictured this year forming living rafts to travel through waters to new areas.

The Invasive Species Council has called on communities in south-east Queensland and northern New South Wales to be on the alert; six nests were reported by a property owner in South Murwillumbah, 13 kilometres south of the Queensland border.

A nest was also identified in mid-December on the Queensland-NSW border at Currumbin Valley.

Why are red imported fire ants a threat?

First detected in Australia in 2001, RIFA are a “triple threat” due to the potential impact on natural ecosystems, agricultural systems and human beings, University of Sydney ecologist and entomologist Dieter Hochuli said.

Cane toads, foxes, rabbits and feral cats might be the more well-known imported pests in Australia, but Hochuli said RIFA could be a much bigger problem.

A RIFA sting can not only be painful, but deadly, especially as the ants tend to attack in large groups rather than one-on-one; a vulnerable person going into anaphylactic shock is a very real risk.

A more common and less life-threatening reaction is the development of small blisters or pustules at the sting site after a few hours, or even a day or two. These may become itchy and can take up to 10 days to heal.

Fire ants have proven to be a “super invader”, quickly monopolising resources wherever they make their nests, making them a big threat for native ants that play a vital role in the country’s ecosystem.

RIFA also feed on native plants and animals, which could potentially lead to the destruction of whole ecosystems.

This fire ant living raft could be deadly if provoked. Photo: Invasive Species Council

Although the goal for some local pests is to get populations down to manageable levels, the aim with RIFA is total eradication due to the havoc they can wreak and their capacity to spread quickly.

“In terms of their current distribution in Australia, it’s very limited,” Hochuli said.

“But that’s really been through extraordinary efforts by various people working in biosecurity for state and federal governments to try and detect them, control them and eradicate them because they have massive, massive nests.

“They’ll produce hundreds of thousands of eggs, and produce thousands and thousands of flying ants that will colonise new places.”

Apart from being able to produce flying ants, RIFA are excellent hitchhikers, and their origins in South America have also enabled them to adapt to wet weather and floods by forming living rafts to travel on top of water.

What can be done to prevent a spread?

Southern Cross University entomologist and chair of science Nigel Andrew said tip-offs from the public are vital to helping authorities prevent the spread of RIFA.

“That’s what happened when they crossed the border last year; when they were found initially, they were identified and the public notified the [Department of Primary Industries],” he said.

“They basically went into the biosecurity framework to remove [the RIFA] as quickly as possible. And that’s how new incursions hopefully will continue to be not just contained, but eradicated.”

The Australian public is strongly encouraged to report possible sightings of RIFA to the National Fire Ant Eradication Program, either via an online form or a call to the hotline: 13 25 23.

Fire ants are between 2mm and 6mm in size, and copper brown in colour, with a darker abdomen. Their nests can look like dome-shaped mounds or be flat and look like a small patch of disturbed soil.

Taking clear photographic evidence is very useful for authorities to determine if there is a threat, but Andrew warned against further taking matters into your own hands as fire ants are very aggressive.

A quick dose of insect spray might be enough to deter regular ants from hanging around your house, but it will only make RIFA angry – and leave you vulnerable to attack.

“You have to be aware that if you’re getting close enough to spray them with fly spray, you might find that they’ve come up behind you and started climbing up your leg,” Andrew said.

“In order to eradicate, they need to be given a bait that is taken by the [worker ants] and fed to the queen.

“And that can take a couple of weeks for a regular baiting to occur, depending on if it’s a small nest or a large one, because sometimes the … nests can have multiple queens in them.”

He said without further funding, any hopes to eradicate RIFA from Australia are futile.

RIFA are already the target of a $596 million national eradication program, but Andrew said it would cost 10 times that much to fully be rid of RIFA in south-east Queensland.

“It’s a big cost to actually eradicate them, but it’ll be 10, 20 times more cost if we have to live with them,” Andrew said.

“It is [an] invasive species which can really change our way of living. It’s a big statement to make, but we do know from what happened in the US, for example, that they do really change [lives] if they’re not eradicated.”