During the era of Mao Zedong in communist China, one day in 1958, it was officially decided that four species were troubling the people and threatening the nation’s agricultural productivity. These species—rats, flies, mosquitoes, and sparrows—were blamed for spreading disease and, in the case of sparrows, for eating valuable grain. Thus began the infamous “Four Pests Campaign,” part of the broader Great Leap Forward. The state of Communist Party of China mobilized millions of citizens to participate in an eradication effort that was as enthusiastic as it was ecologically naïve.

Sparrows, especially the Eurasian Tree Sparrow, were seen as class enemies of grain. People were highly enthusiastic about exterminating sparrows, and the equipment and techniques used were surprisingly advanced. These included shooting them with shotguns, poisoning, setting up “grain traps,” destroying nests, and smashing eggs to wipe out future generations. In Sichuan, people coordinated with one another and adopted a “military-style mass mobilization” approach, launching collective attacks every time sparrows were targeted—delivering devastating blows to the birds. In Shanghai, free shooting zones were set up in parks and other open areas, and bird hunting became a trendy activity among city residents. Perhaps at the time, when people met each other, the first question wasn’t “Have you eaten?” but rather, “How many sparrows did you shoot today?”

Citizens banged pots, drums, and anything else that made noise to prevent sparrows from landing, thereby exhausting them to death. It worked—tragically. Sparrows dropped from the skies, including in foreign diplomatic compounds. In one peculiar episode, hundreds of Chinese gathered outside the Polish embassy in Beijing, frantically drumming to prevent sparrows from seeking asylum among the trees on embassy grounds. The Polish staff reportedly collected piles of dead birds with shovels—an undiplomatic task, to say the least.

By 1960, the ecological consequences became undeniable. Sparrows, it turned out, didn’t just peck at grain; they also consumed vast numbers of crop-eating insects. With their predators gone, locusts and other pests flourished. As insect populations surged, grain yields plummeted. The campaign had, quite literally, backfired. Between 1959 and 1961, an estimated 15 to 45 million people perished in the Great Chinese Famine, one of the deadliest in human history. While the causes were complex—ranging from flawed agricultural policies to natural disasters—the extermination of sparrows played no small role.

Eventually, Mao admitted the mistake. Sparrows were quietly dropped from the list of pests and replaced by bedbugs—who, to their credit, didn’t fly into embassies or eat locusts. To repair the damage, China imported 250,000 sparrows from the Soviet Union in a desperate, winged bailout. But by then, the ecosystem had already been thrown into chaos.

Thus, the Four Pests Campaign remains a sobering lesson in unintended consequences—and proof that declaring war on birds can come home to roost.