What was the Four Pests Campaign?

In this episode of Stuff You Should Know, Josh and Chuck discuss the Four Pests Campaign in China from the late 1950s to the early 1960s. They detail Mao Zedong's initiative to eradicate rats, sparrows, flies, and mosquitoes to improve public health and boost agricultural output as part of the Great Leap Forward. The hosts explore the motivations behind the campaign, the methods used, and the disastrous unintended consequences, particularly the ecological imbalance caused by the removal of sparrows, which led to increased locust populations and contributed to the Great Famine. They also touch on the political factors, such as unrealistic quotas and the suppression of accurate reporting, that exacerbated the famine, and the long-term impacts of the campaign on China's environment and public health policies. The episode concludes with a listener mail segment where they clarify a joke from a previous episode.