Rat extermination is a traditional technique that dates back thousands of years to the dawn of human civilization, with the earliest rat poisons traceable to the pre-Qin period.
In "The Classic of Mountains and Seas, The Classic of the Western Mountains," it is recorded that on Mount Gao Tu, "there is a white rock called Ju, which can poison rats. There is also a grass that looks like Yaobai with leaves like mallow but with a red back, named Wu Tiao, which can also poison rats."
Originally utilizing plant or mineral toxins, by the 19th century, rat poisons had become diverse and numerous, with as many as a hundred different kinds.
The dreaded name "Black Death" was so significant that, upon receiving the notice from the Vienna Government, European countries expressed their support, albeit somewhat confusedly.