The shift signals a potential loss of control over what experts call one of the world’s worst invasive species. A widespread infestation could devastate agriculture, tourism, biodiversity, and public access to outdoor spaces across Maui, threatening schools, parks, and community life.
Little fire ants have reached a critical tipping point on Maui, with detections surging sharply in 2024 after years of controlled spread, according to the Maui Invasive Species Committee. The invasive species, first discovered on the island in 2009, was found at an average of two new locations per year until 2024, when that pattern shattered with eight new sites identified in a single year.
“We’re on the brink of winning or losing,” said Lissa Strohecker, the committee’s outreach and education specialist. “We don’t want this to fail.”
The Crisis and Control Challenges
For Scott Fisher, an ecological-restoration leader with Hawaiʻi Land Trust, the crisis became concrete when he learned a fire ant had been detected at Waihe’e Coastal Dunes and Wetlands Refuge on Maui’s north shore. The refuge had remained ant-free until now, despite infestations on nearby land since at least 2024.
“I don’t know how to describe the emotion, but it was visceral,” Fisher said. “My kids grew up swimming in this river, and to consider the fact that they would no longer be able to enjoy it the way that I want them to — and that their kids can’t enjoy it — that’s devastating.”
The refuge draws thousands of children for education programs annually. A widespread infestation would halt restoration projects, move classes indoors, and suspend camping to prevent stings while treatment proceeds.
As of September, the committee had identified little fire ants at 28 locations across Maui: 12 in active treatment, seven being monitored, and nine successfully eradicated. But about 40 percent of infestations are on private property, complicating control efforts. By the time the committee receives a report, the ant population has often already spread across two to three acres.
Three of every four detections come from community members rather than official monitoring, underscoring the effort’s dependence on public awareness. Infestations have been documented across the island — from Kīhei and Kapalua to Nāhiku, Haʻikū, and Hāna.
Detection and Treatment
The committee operates with a seven-person team and approximately $2 million in annual state and local funding. The group uses treatments developed by the Big Island-based Hawaiʻi Ant Lab, including an approach that deploys ant birth control from helicopters and drones.
A key addition is an ant detection dog named Freddie, a 4-year-old black Labrador trained in Brisbane, Australia. The committee purchased Freddie in 2024 for $45,000 with support from three foundations and the Hawaiʻi Invasive Species Council. Freddie helps field crews locate ant hotspots and confirm the presence or absence of infestations — work that might otherwise require extensive surveys.
“After the first year, a field crew returns to the site of an infestation and examines it for any sign of ants, which is like looking for a needle in a haystack. That’s where the ant detection dog Freddie comes in handy,” the committee noted.
Treatment follows a methodical protocol. In the first year, crews apply ant bait mixed with s-methoprene — a growth inhibitor that prevents reproduction — every six weeks. “It’s very low impact,” said Brooke Mahnken, the committee’s data manager and a former fire ant coordinator. “But if you stop feeding it to them, they can come back and start to reproduce again.”
After year one, crews return to surveyed areas to check for remaining ants, repeating treatment wherever the insects persist. Only after no ants are detected does the extended surveillance phase begin. The area is then monitored for five additional years before the population is considered eradicated.
Mahnken described the process plainly: “It is meticulous, arduous, iterative, long-term work to do eradication.”
The Stakes and Community Action
Little fire ants form supercolonies of millions that overwhelm other insect species. “Once they establish and their population starts growing, they will infest every square inch in the three-dimensional space,” Mahnken said. “When that happens, it’s an incredible loss of biodiversity. Almost everything else is killed or eaten or driven out.”
The ants deliver painful stings if disturbed in vegetation or dislodged from trees. Pets, livestock, birds, and other animals can go blind after repeated stings.
The committee is pursuing additional funding sources, including money from the state’s new environmental green fee assessed on tourists. Strohecker urged community members to educate themselves on fire ant risks and report suspected sightings.
“You want to find them before they find you,” she said.
Community members are encouraged to inspect high-risk items — potted plants, soil, mulch, and landscaping materials — before bringing them into homes and yards. Collection kits are available online and at some local garden supply stores. Collected ants are mailed to the committee, where technician Monte Tudor-Long examines them under a microscope to confirm identification.