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

A severe mouse infestation is wreaking havoc across extensive regions of Australia, with rodents invading homes and destroying grain crops. This crisis adds to existing stresses on agricultural producers, who are already grappling with volatile fuel and fertilizer costs driven by the ongoing conflict between the US, Israel, and Iran. Consequently, farmers are spending hundreds of thousands of dollars to either replant crops consumed by the pests or dedicating valuable time to deploying bait—seeds treated with poison to eliminate the rodents.

Geoff Cosgrove, a 43-year-old farmer managing a 14,000-hectare property in Mingenew, Western Australia (WA), where he cultivates wheat, canola, lupins, and barley, highlights the financial and psychological toll. "It's a big cost and it's not just the price of the bait," Cosgrove explains. He describes the psychological strain of the infestation: "They do play with your mind - running around at night, in the ceiling, the air conditioning units. You can hear them and you can smell them - it's like a decaying body."

With 25 years of farming experience, Cosgrove notes that he has only needed to conduct baiting operations twice previously. He describes the current outbreak as "way worse than the one in 2021." That earlier plague severely impacted New South Wales (NSW) and parts of Queensland, marking the worst infestation in living memory for many areas. The situation in NSW was so critical that hundreds of inmates had to be relocated due to extensive damage caused by mice within the prisons.

In contrast, this year’s crisis emerged slightly later, with farmers in WA reporting plague-level mouse populations starting in March, followed closely by neighbors in South Australia.

Bumper harvest boosts mice numbers

Approximately two hours north of Cosgrove’s farm, 59-year-old agronomist and farmer Belinda Eastough remembers the WA mouse plague from five years ago. Speaking from her 5,500-hectare property in Nolba—located 80km (50 miles) northeast of Geraldton, one of the hardest-hit regions—she recalls, "The last time [in 2021], they were in my handbag."

While mice invaded her floors, walls, and pantry during the 2021 outbreak, Eastough notes that this year, "they're staying where the food is," which is primarily in the paddocks. "Last year, we had a record-breaking harvest so that gives the mice a lot of food," she explains. The abundant harvest resulted in significant grain spillage during crop processing, providing an easily accessible and preferred food source.

This food supply was further augmented by summer rains, which encouraged the growth of young green shoots. "Then we got some summer rain," Eastough says. "So instead of just steak, they got steak and salad. Basically, the mice were in absolute mouse heaven."

Eastough, who has farmed for nearly four decades, grows wheat, canola, and lupins. Her wheat is either exported to Southeast Asia for udon noodle production or used domestically for biscuits, bread, and pasta. In her canola fields, she estimates mouse densities of 8,000 to 10,000 per hectare—an area roughly the size of a rugby field.

"Sometimes we've had mouse plagues, and the numbers will crash once they run out of food but this year, they haven't," she says. "I'm living the nightmare."

'Another headache'

Autumn is a critical period for grain growers as it is the primary planting season. As an agronomist, Eastough advises producers to bait fields immediately after seeding. "If the baiter hasn't followed quickly enough behind the seeder, the mice are coming along at night and eating the seed out of the furrows," she warns. "If you finish seeding at 8pm at night and you come in the next day, you'll have rows of crop missing."

Although farmers have demonstrated resilience, Eastough points out that rising diesel and fertilizer prices have significantly impacted operations since the outbreak of the Iran war in February. "We're paying twice for fuel now than we were paying two, three months ago," she states. "The mouse thing is another thing thrown on top, another headache."

Steve Henry, a research officer with Australia's national science agency, CSIRO, specializes in mouse ecology and eradication strategies.

Source: BBC News Generated at: 2026-05-30 20:58:05 UTC