In rural China, especially in the northern regions, before sowing, people often scatter some “poisoned grain” or “poisoned millet” in the fields. This practice helps to kill pests like mole crickets and field mice.
At first glance, “poisoned grain” and “poisoned millet” look similar to ordinary grains and millet. So why are they so effective?
It turns out that these are bait laced with poison specifically prepared for mole crickets, field mice, and other pests!
You’ve likely heard of “arsenic.” The chemical compound in arsenic is arsenic trioxide, commonly known as “arsenous acid.”
Arsenic trioxide, depending on the impurities it contains, can come in two colors: white or red. The white version is commonly called “arsenic” or “poison crystal,” while the red version is known as “poison stone,” “earth poison,” or “red alum.” Poisoned grain and poisoned millet are made by soaking grains and millet in a solution of arsenic trioxide.
In very small amounts, arsenic trioxide is not only non-toxic to humans but can even be beneficial, which is why arsenic is sometimes used in medicine. However, consuming slightly more than this can be lethal to humans. As for pests like mole crickets and field mice, they fear it greatly. Just one percent of a gram of arsenic trioxide is enough to kill a field mouse within a few hours.
Why not just spray arsenic trioxide directly onto the fields like pesticide? That’s because arsenic trioxide is very expensive, can severely burn crops, and is unsafe for humans and animals. So instead, people create poisoned grain and poisoned millet to eliminate pests.
It’s best to scatter poisoned grain and millet in the fields before sowing, rather than mixing them with seeds, as doing so could cause chemical damage and affect seed germination. Additionally, it’s important not to use too much—about 3 pounds per acre is enough.