WESTERN AUSTRALIA — A severe mouse plague is devastating farms across Western Australia in 2024, with rodent populations reaching thousands per hectare and destroying newly planted crops. Farmers first reported plague-level mouse numbers in March 2024, as mice began consuming seeds sown during the critical autumn planting period.

Geoff Cosgrove, who operates a 14,000-hectare farm in Mingenew, Western Australia, growing wheat, canola, lupin, and barley, said the 2024 outbreak is worse than the 2021 plague. "It's a big cost and it's not just the price of the bait. 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," Cosgrove said.

Belinda Eastough, a farmer and agronomist from Nolba, Western Australia, estimated mouse densities of 8,000 to 10,000 per hectare in her canola paddocks. She attributed the surge to a record-breaking 2023 harvest that left spilled grain in fields, followed by summer rains that promoted fresh plant growth. "So instead of just steak, they got steak and salad. Basically, the mice were in absolute mouse heaven." She noted mice are staying in paddocks this year rather than entering homes. "They're staying where the food is," she said.

Steve Henry, a CSIRO research officer specializing in mouse eradication, confirmed extreme infestations across Western Australia’s northern and southern cropping zones. "But in Western Australia, they're talking about thousands and thousands of mice per hectare," Henry said. During a field visit, he observed 30 to 40 active burrows in a 100-meter by one-meter strip, suggesting population densities far exceeding the 800 mice per hectare threshold that defines a plague. He also described the psychological toll. "If you're dealing with a drought, you can go inside and close the door and turn on the air conditioner and get some level of respite. But if you're dealing with mice, you go inside, close the door, go to your cupboard, and the mice are in the cupboard. You go to sleep at night, and the mice are running across your bed," he said.

Farmers are spending hundreds of thousands of dollars replanting destroyed crops or laying bait containing sterile seeds laced with poison. They had also sought access to stronger bait, pending approval from the national regulator.