Why are red fire ants causing alarm in Queensland and beyond?

A deadly resurgence of red imported fire ants is gripping southeastern Queensland following the aftermath of Cyclone Alfred. Heavy rains in early March appear to have accelerated the invasive species’ spread, triggering a surge in stings and hospitalisations, according to state health and agricultural authorities. More than 60 people have reportedly been stung, with 23 requiring hospital care. Among the casualties was a young puppy found dead on a nest, underscoring the danger posed to domestic animals as well as wildlife and humans.

The Australian Broadcasting Corporation and CNN cited firsthand accounts from rural residents describing how fire ants are “everywhere,” invading homes, patios, farming equipment and livestock paddocks. As infestations multiply and spread beyond previous containment lines, public concern is mounting over the effectiveness of current eradication strategies and whether enough is being done to prevent the fire ants from becoming a permanent fixture in the Australian landscape.

How did red imported fire ants become a threat to Australia?

The red imported fire ant (Solenopsis invicta) is native to South America but has become one of the world’s most destructive invasive species. The ants were first detected in Brisbane in 2001, likely arriving in cargo shipments via international ports. Since then, they have colonised vast stretches of Queensland, with incursions documented in New South Wales and the Murray-Darling Basin. The ants’ extraordinary adaptability allows them to thrive in a variety of climates and terrains, and their ability to form floating colonies during floods has enabled them to spread rapidly after major weather events like Cyclone Alfred.

Globally, red fire ants have already established populations across the southern United States, parts of China, and most recently in Europe, where they were detected for the first time in 2023. In each case, their presence has caused economic and ecological disruptions—damaging crops, displacing native species, and burdening public health systems due to their painful and sometimes life-threatening stings.

What are the health and economic risks of red fire ants in Australia?

The threat posed by red fire ants extends far beyond nuisance bites. Their venom can trigger pustules, allergic reactions, and in rare cases, anaphylactic shock. Australian medical experts estimate that unchecked fire ant spread could result in up to 570,800 medical consultations and as many as 30 deaths per year. The psychological toll on residents, particularly in rural zones where outdoor work is routine, is also growing.

Economically, the stakes are enormous. Modelling by the Invasive Species Council suggests that fire ants could cost the Australian economy up to A$2 billion annually if left to proliferate. These costs include not only healthcare expenses but also lost agricultural productivity, veterinary bills, biosecurity controls, and long-term environmental rehabilitation. Damage to infrastructure, such as electrical equipment and irrigation systems, is also common where colonies establish themselves.

Ecologically, the ants are devastating. A 2022 study estimated that 38% of mammals, 45% of birds, 69% of reptiles, and 95% of frogs in Southeast Queensland are at risk of population decline due to predation and habitat disruption from fire ants. Their aggressive territorial behaviour also displaces native ant species, leading to broader imbalances in the food chain and ecosystem.

What is being done to contain and eradicate the fire ant invasion?

The Queensland government has earmarked an additional A$24 million to support suppression and eradication efforts, bringing total spending to around A$61 million. Authorities have deployed aerial baiting programs using helicopters, drones, and light aircraft to disperse granular insecticides over known colonies. On-ground teams also use all-terrain vehicles and handheld devices to deliver treatment in more targeted areas.

However, critics argue that the current approach is neither sufficiently resourced nor strategically implemented. Under a national eradication plan, landholders in inner suppression zones are expected to treat infestations themselves using bait delivered upon request. Residents, including horse agister Kirsty McKenna, say they have received minimal support beyond mail-delivered poison, despite facing “hundreds” of new nests on their land. Others report delays in inspections and restrictions on moving hay, turf and soil, which complicate their livelihoods.

A perimeter has been established around the core infestation zone to slow the outward spread. Still, experts warn that the ants are expanding at a rate faster than containment teams can keep up. Biosecurity Queensland has acknowledged that wet weather and public non-compliance with restrictions have hampered progress.

What challenges are hindering Australia’s fire ant response?

Community engagement remains one of the most difficult elements of the fire ant eradication program. Public compliance with chemical treatments has been uneven, particularly in areas where residents are concerned about potential risks to pets, livestock, or organic certification. In some instances, eradication teams have faced active resistance. A recent confrontation in Samford Valley led to the arrest of a woman who blocked authorities from spraying bait on her property.

These tensions reflect a broader mistrust of government-led pest control campaigns, which some residents feel are implemented with little transparency or local input. At the same time, the scientific community has stressed that eradication is only feasible with unified action—partial treatments or untreated zones create safe havens for colonies to regenerate and spread.

The issue is further complicated by funding uncertainties. Although the national eradication plan targets complete removal by 2032, successive reviews have questioned whether current allocations are sufficient to meet that goal. With climate change likely to increase the frequency of floods and warm temperatures that facilitate ant migration, some entomologists believe the window for eradication may be closing rapidly.

Can red fire ants still be eradicated from Australia?

Despite the challenges, many scientists and government officials believe there is still a narrow path to eradication—if action is taken quickly and comprehensively. Lessons from the United States and Taiwan, where fire ants are now entrenched, suggest that delay results in permanent establishment, after which only long-term suppression, not elimination, is possible.

Dr. Ben Hoffmann, a fire ant expert with CSIRO, has argued that Australia is better positioned than most countries to attempt full eradication due to its geographic isolation and previous success with biosecurity efforts. However, he cautioned that containment requires aggressive, consistent treatment, community cooperation, and sustained government investment over a decade or more.

In the meantime, residents in affected areas are being urged to avoid disturbing fire ant nests and to report sightings through official state channels. Treatment zones must remain undisturbed for at least 48 hours post-application, with restrictions on moving soil or organic material out of the area without inspection.

Ultimately, the scale of the challenge posed by red imported fire ants is becoming increasingly clear—not just to scientists and policymakers, but to everyday Australians encountering them in backyards, paddocks and public spaces. Whether eradication remains within reach will likely depend on how swiftly and cohesively Australia can rally the necessary resources and public resolve.