In the late 1950s, China launched a campaign known as the Four Pests Campaign, aimed at reducing the population of four creatures deemed harmful to public health and agriculture: sparrows, rats, flies, and mosquitoes. The initiative was part of a broader effort to improve living conditions and increase food production. According to some estimates, as many as two billion sparrows were killed during this period, although other sources suggest the number was closer to 200 million in 1958 alone. The campaign was driven by the belief that sparrows were damaging crops, a view that was later challenged by scientific research. The campaign was heavily influenced by Mao Zedong, who publicly endorsed the elimination of sparrows. However, in 1959, the Chinese Academy of Sciences conducted studies that showed sparrows primarily ate insects, not seeds. This meant that sparrows were actually helping to control insect populations, including pests like locusts. Despite this evidence, the campaign continued, leading to a sharp rise in insect numbers, which in turn affected crops. The ecological impact of removing sparrows had serious consequences for agriculture. Studies indicate that areas with high sparrow populations experienced a decline in rice and wheat yields—by 5.3 percent and 8.7 percent, respectively. These drops, along with other factors like poor weather and mismanagement, are thought to have contributed to the Chinese Great Famine, which caused an estimated 16.5 to 45 million deaths between 1959 and 1961. Some research, including a study from the University of Chicago, suggests that the sparrow extermination may have been responsible for nearly 2 million of these deaths. Realizing the mistake, the Chinese government eventually stopped the campaign. To help restore the ecosystem, they imported 250,000 sparrows from the Soviet Union. This move underscored the unintended and far-reaching consequences of the campaign, highlighting the importance of ecological balance in agricultural planning.