Australia is in the midst of a war that is going on for longer than a century. This war is against the animals that are living on this continent. The first registered plague that the Australians had to fight against was the rabbit plague of 1859. A fight in which the rabbits killed native bushes, ringbarked trees, and shrubs by digging up their roots. Pastoralists had little left to feed their animals due to a combination of overstocking, drought, and rabbits. What does today's topic have to do with this old piece of history? The answer is simple. The mice plague of 2021 and the rabbit plague of 1859 was triggered by the warm environment of the country combined with the lack of natural predators. But what caused the new outburst in mice?
Following many years of severe drought, which culminated in the disastrous bushfires of 2019–2020, eastern Australia had abundant rainfalls during much of 2020, notably in agricultural regions. These rains let crops grow, and the fires killed predators of the mice, allowing the small opportunistic animals to feed on almost anything and reproduce without worries. The territories of Queensland and Western Australia were, and still are, the most affected. Citizens of those regions woke up terrified because the mice were in their houses, rooms, and even beds, and not in small numbers at that. From the begging of March until June 2021, the mice were ruining everything and anything in their desperate search for something more to feed on. Devastating farmlands, raiding convenience stores, running across classrooms, and even causing the relocation of a prison’s population because they chewed through the facility’s electrical infrastructure, the mice wouldn’t stop at just that.
In March last year in New South Wales, there were cases of patients being bitten by mice. This happened to citizens hospitalized in three different hospitals in the region and there was also a confirmed case of lymphocytic choriomeningitis, a mouse-related illness. Even though in an interview, the public health director Priscilla Stanley said that she was surprised there weren’t that many people who contracted a rare rodent-borne infectious disease, the hospital incidents underline the severity of the mice plague.
The agriculturalists are still the most affected by this infestation. The mice were ruining crops, destroying the stored hay and inside silos in big numbers, and they were also discovered inside of the agriculture machines. In spite of that, the farmers were the ones who acted the fastest in the fight to save their crops. Quickly many of the hardware stores run out of conventional mouse traps so the agronomists had to improvise. Some of them used traditional methods such as buckets of water with a peanut butter lure inside of it and their rims coated in vegetable oil, and some are turning whole shipping containers into traps. “The trick for this kind of trap is to lure the mice in their hundreds in at one end of the container and funnel them through to the bait and the prepared drowning tank at the other end.” - a BBC article explains.
Those methods are working, indeed, but for the big number of mice most of the farmers started using poison. Roger Woods is a farmer from Queensland who pioneered the use of drones for agricultural use. With the mice invading his and the other farmers' lands and crops, he thought of the idea to implement a new eradication method for the rodents. The technology of his procedure is fairly easy to understand. The drones have installed on them some small hoppers that drop grains laced with Zinc phosphide. After the mice ingest this grain, the latter produces phosphine gas that quickly kills the mice.
The problem with the use of poison is that, yes it does kill the mice in the area after 24 hours, but at the same time it remains active for months. The predators that find the life-less prey eat it and now the poison stays in the ecosystem, slowly destroying it. The poison from the drones can easily be eaten by domestic animals such as cats and dogs, or by birds and fish thus killing all of them.
The plague of mice seemed to cease at the end of the last year. This was thanks to the persistent rains, prolonged flooding, and the diligent baiting made by the farmers. All of those factors helped to stop the infestation that caused millions of dollars of damage and terrorized the citizens of Australia for a year. Unfortunately, this is not the end of the war against mice, and farmers should still be alert in case they see the numbers of rodents increasing again. Let’s not forget that zinc phosphide is not only killing the mice, but also other animals and it can endanger humans. The Australians need to find new ways of battling the small animals because they can’t keep on poisoning their own lands forever.