Western australia: Farmers across Australia are grappling with a severe infestation of billions of rats, causing extensive damage to agricultural land and residential areas in the southern and western regions of the country, particularly in Western and South Australia.
According to Thai News Agency, local media reports that this outbreak began severely in Western Australia, including towns like Mingeneau, Morawa, and Malleva, as early as March, before spreading to South Australia. Farmers in the area state that this rat infestation is far more severe and difficult to manage than the major crisis in 2021, due to environmental conditions and the abundance of local food sources. Last year, Australia had a record-breaking agricultural harvest, resulting in a large amount of unharvested grain in fields, providing an excellent food source for the rats. Furthermore, heavy summer rains stimulated the growth of treetops and leafy plants, further enriching the rat food supply with both primary and supplementary food sources.
The rat species found to be causing the infestation is the European house rat (Mus musculus), an invasive species in Australia. They can reproduce as young as 6 weeks old, giving birth to 6-10 pups every 19-21 days, causing their population to multiply exponentially in a short time.
The Commonwealth Institute for Scientific and Industrial Research (CSIRO) estimates that in the most affected areas, rat densities reach as high as 8,000 per hectare, ten times higher than the government-defined threshold for a "critical rat population." This crisis occurs during the autumn, the primary growing season for farmers, when swarms of rats sneak in at night to feed on newly sown seeds such as wheat, canola, and lupin, preventing crop growth. Many farmers are forced to replant multiple times. Farmers are already burdened with rising farming costs, including doubled diesel and fertilizer prices.
Meanwhile, rats are no longer confined to rice fields but have begun invading homes, kitchens, food storage areas, and barns. Villagers and farmers in the area report catching an average of 20-30 rats a day in their homes and more than 150 a day in storage areas. Residents are forced to live amidst foul odors and gnawing damage, and live in constant fear as rats scurry everywhere, even onto their beds at night.
The Australian Bureau of Agriculture and Drug Administration (AOADA) has approved an emergency permit allowing farmers to use double-concentration zinc phosphide baits, which are more than 80% effective at eliminating rats. Farmers are advised to immediately place the bait in trucks after seed planters to prevent rats from burrowing and eating the seeds in the furrows.
Farmers and experts expect the rat population to naturally decline as winter approaches, as the cold, wet weather and food shortages will help halt their reproduction.