It’s like a decaying body’: Australian farmers battle mouse plague

It s like a decaying body – Australia’s agricultural sector is facing an unprecedented challenge as a mouse plague intensifies across vast regions, disrupting both rural livelihoods and daily life. Rodents have become a constant threat, infiltrating homes and devouring essential crops. This crisis adds to the existing pressures on farmers, who are already contending with fluctuating fuel and fertilizer prices due to the ongoing US-Israeli conflict in Iran. The situation has forced many to allocate significant financial resources toward replanting lost crops or investing time in baiting fields with poisoned seeds.

Geoff Cosgrove, a 43-year-old farmer in Mingenew, Western Australia, describes the chaos firsthand. Managing a 14,000-hectare farm, he grows wheat, canola, lupin, and barley. The mice, he says, have turned his fields into a battlefield. “It’s not just the cost of the bait,” Cosgrove explains. “They mess with your mind—running around at night, scurrying through ceilings and air conditioning units. You can hear them and smell them, like a decaying body nearby.” Cosgrove, who has been farming for 25 years, recalls only having to use bait twice in his career. This year, however, the plague is “way worse than the one in 2021,” he adds.

The 2021 outbreak was a grim reminder of the devastation mice can cause. Entire regions in New South Wales and parts of Queensland faced their most severe plague in decades. In NSW, the crisis was so dire that hundreds of prisoners had to be relocated after mice damaged facilities at a detention center. Now, the current surge is hitting Western Australia first, with reports of plague-like numbers emerging in March. Soon after, similar concerns spread to South Australia, creating a widespread emergency.

Belinda Eastough, an agronomist and farmer from Nolba, 80km northeast of Geraldton, reflects on the 2021 plague. “They were in my handbag,” she recalls from her 5,500-hectare farm. “They were everywhere—floors, walls, even the pantry.” But this year, she notes, the mice have shifted their focus. “They’re staying where the food is,” she says, pointing to the paddocks. “Last year, we had a record harvest, which left a lot of grain scattered during processing. That’s what attracted them.” The combination of abundant food and summer rains created ideal conditions for the rodents to thrive. “Instead of just steak, they got steak and salad,” Eastough explains. “It was absolute mouse heaven.” Her paddocks now host 8,000 to 10,000 mice per hectare, roughly the size of a rugby field.

“They mess with your mind—running around at night, scurrying through ceilings and air conditioning units. You can hear them and smell them, like a decaying body nearby.” – Geoff Cosgrove

Eastough, with nearly four decades of farming experience, emphasizes the urgency of action. “The autumn is one of the most critical times for grain growers, when they plant their crops,” she says. This year, she’s urging farmers to start baiting immediately after sowing. “If the baiter lags behind the seeder, mice come at night and eat the seeds from the furrows,” she warns. “You might finish seeding at 8pm and return the next day to find entire rows missing.” Despite their resilience, Eastough says rising diesel and fertilizer costs have compounded the problem. “We’re paying twice as much for fuel now compared to two or three months ago,” she says. “The mouse issue is just another burden to add to the stress.”

Steve Henry, a research officer at Australia’s national science agency CSIRO, provides insight into the scale of the infestation. He defines a mouse plague as 800 rodents per hectare but notes that in Western Australia, numbers have skyrocketed to thousands. “In the northern and southern cropping zones, we’re talking about massive populations,” Henry says. During a recent visit, he observed 30 to 40 active burrows over a 100-meter stretch of a one-meter-wide strip. Multiplying that figure by 100, he explains, gives an estimate of the population density—equating to 3,000 to 4,000 burrows per hectare. The situation in South Australia mirrors this trend, creating a nationwide crisis.

“We’re paying twice as much for fuel now compared to two or three months ago. The mouse issue is just another burden to add to the stress.” – Belinda Eastough

As the autumn planting season approaches, farmers are scrambling to mitigate the damage. Eastough, who advises on crop management, highlights the importance of timing. “If you delay baiting, the mice will have already feasted on the seeds,” she says. The threat isn’t limited to crops; it’s a full-blown invasion of homes and infrastructure. Cosgrove’s farm, for example, has seen mice infiltrate living spaces, creating an environment where the pests are both a physical and psychological menace.

The economic toll of the plague is significant. With fuel and fertilizer prices surging, farmers are already stretched thin. The cost of baiting and replanting further strains their budgets. “This is a really important time for farmers,” Henry says. “If they don’t act quickly, the damage can be irreversible.” The rodent problem has also disrupted the normal rhythm of farming, forcing many to work longer hours or divert resources to pest control. In some cases, this has delayed other essential tasks, compounding the challenges they face.

Experts warn that without effective intervention, the situation could worsen. The 2021 plague was a turning point, revealing how easily mouse populations can spiral out of control under favorable conditions. This year’s outbreak is even more severe, driven by a combination of factors including a record harvest, summer rains, and the availability of food in the paddocks. “Mice are opportunistic,” Henry explains. “They thrive when there’s abundance, and this year, the conditions are perfect.” The national science agency is working closely with farmers to develop strategies for long-term control, but the immediate challenge remains daunting.

For Cosgrove, the plague has tested his patience and resourcefulness. “It feels like a never-ending battle,” he admits. “You’re always looking over your shoulder, wondering if the next row will be safe.” Eastough echoes this sentiment, describing her experience as “living the nightmare.” Despite the hardships, both farmers remain determined. “We adapt,” Cosgrove says. “But this year, it’s been a different kind of fight.” As the season progresses, their efforts will be critical in determining whether the agricultural heartland of Australia can weather this crisis.