Mouse Plague Devours WA Crops: $50M Losses Loom

Western Australia's grain belt is currently experiencing a severe mouse plague, with rodent populations reaching ten times plague proportions in some areas. This infestation began in March 2026 and has since caused widespread crop damage, with farmers estimating losses exceeding $50 million. The overwhelming smell of mice, a combination of urine, feces, and decaying bodies, has become a constant presence in affected towns.

Farmers have resorted to using a stronger, fast-acting zinc phosphide bait (ZP50), classified as a dangerous poison, to combat the overwhelming numbers. This substance, approved for emergency use by federal regulators, carries risks to wildlife. Permits for its use in WA faced delays, with farmers expressing frustration over the late arrival of effective bait. Concerns were raised about potential impacts on non-target species, although permits were granted in South Australia prior to plague levels being reached.

The agricultural sector in WA, a major global grain exporter, is facing substantial financial strain. Damaged canola fields resemble "Swiss cheese" due to mice stealing seeds and young plants, leading to potential replanting and financial struggles for many farmers. The psychological burden on residents is immense, with mice invading homes and businesses, forcing extreme measures to protect food supplies and community facilities.

Experts note that mouse plagues follow a typical trajectory of rapid population growth followed by a dramatic crash due to factors like increased competition, disease, and cannibalism. Whether the current outbreak in WA and South Australia is nearing its end or is midway through a two-year cycle remains uncertain. Communities continue to bait and hope for a swift resolution, mirroring past plague disappearances.