For Stanley Tipungwuti, the sting of a tropical fire ant was personal. The ranger on Melville Island, where most residents identify as Aboriginal or Torres Strait Islander, has seen the invasive species leave red, itchy welts on neighbors' skin—and worse. "The ants have a huge impact on native birds and animals on the Tiwi Islands," Tipungwuti told Mongabay. "They can do a lot of damage."
The tropical fire ant (Solenopsis geminata) arrived on these islands off Darwin, the capital of Australia's Northern Territory, in the early 2000s—likely stowing away on ships centuries after their ancestors sailed with European colonizers. Once established, the ants flourished, forming massive colonies that devoured small mammals, attacked vulnerable sea turtle hatchlings, and deterred nesting birds.
But after twenty years of painstaking work, the Tiwi Ranger team has achieved something entomologists are calling extraordinary: complete eradication of the species from Melville Island. In 2025, Ben Hoffmann confirmed the ants were no more. That same year, the rangers received the Territory Indigenous Natural Resource Management Award in Darwin.
The scale of the achievement sets it apart globally. The treated area spans 1,535 hectares—far larger than any previous tropical fire ant eradication. "There have been very few tropical fire ant eradications around the world, and when they have been done, they have been incredibly small, from one nest to one hectare or so," said Hoffmann, a principal research scientist at Australia's national research agency, CSIRO, who helped launch the program. "After we began, we realized we had to change our methods from broadscale treatment to painstakingly locating individual nests and poisoning them."
Nigel Andrew, an entomologist and chair of science at Southern Cross University, described the victory in even bolder terms. "This is one of the top three eradications of any invasive ant species worldwide," he told Mongabay. "For something like this to be successful, there needs to be complete, one hundred percent eradication, and a guarantee that all the nests have been destroyed, which can take years as you systematically move through the sites."
The ranger program itself grew alongside the eradication effort. When the ants first arrived, no dedicated team existed—local council and housing operations handled early responses. But over two decades, more than 40 rangers joined the fight, supported by the federal Indigenous Rangers Program. Their method was methodical: locate nests hidden across the landscape, apply Amdro insecticide bait, then monitor sites repeatedly to ensure no survivors remained.
Tipungwuti hopes the lessons learned here will travel further. "There could be a chance for this program to be used in other parts of Australia, like Ashmore Reef," he said. For Hoffmann, the Tiwi story demonstrates what becomes possible when Indigenous knowledge meets sustained scientific partnership. "It is an amazing feat," he said.