Mouse Plague In Western Australia - Between 3,000 and 4,000 Mouse Burrows Per Hectare In Some Areas

Grain growers are on high alert as mouse numbers in Western Australia reach plague proportions and numbers surge in South Australia. Steve Henry, who researches mice and their impact on the grain industry at CSIRO, says more than 800 mice per hectare is considered a plague. “In Western Australia we’re now using the P word,” he said. “We’re getting reports out of Western Australia of 3,000 or 4,000 burrows per hectare.”

“That’s real cause for concern. It’s a plague under any circumstances.” Areas around Geraldton – about 400km north of Perth – were most affected, with similar reports coming in from southern parts of the WA wheatbelt.

On the Adelaide plains, mouse numbers were already “extremely high” and “very concerning for farmers”, Henry said.The 2020-21 plague in eastern Australia caused an estimated $1bn damage. It exposed people and their pets to pesticides and disease, increased stress, and affected the health of livestock (due to contamination of feed and water with mouse urine and carcasses).

The current situation could rapidly escalate. Female mice could start breeding from six weeks old, producing up to 10 babies every 19-21 days.The latest CSIRO mouse forecast recommended farmers monitor mouse activity, consider applying baits at seeding in areas of high activity, and reduce the availability of other food sources.

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https://www.theguardian.com/environment/2026/apr/22/mouse-plague-hits-wa-grain-farmers-as-numbers-surge-in-sa-you-literally-cant-get-away-from-them