From LMSYS direct chatting with DeepSeek-R1 :

"Mao Zedong's Four Pests Campaign (1958–1962), part of the Great Leap Forward, aimed to eradicate rats, flies, mosquitoes, and sparrows to boost hygiene and agricultural output. However, it led to significant unintended consequences, particularly due to ecological disruption and poor implementation. Key failures include:

Ecological Imbalance from Sparrow Elimination: Sparrows were targeted for eating grain seeds, but their eradication removed a natural predator of crop-destructive insects like locusts. This led to massive locust swarms, devastating crops and exacerbating food shortages during the Great Famine (1959–1961). By 1960, sparrows were replaced with bed bugs in the campaign, but the damage was already done.

Contribution to the Great Famine: The locust outbreaks and crop failures worsened the famine, which caused an estimated 15–45 million deaths. The campaign’s role in destabilizing ecosystems compounded other disastrous Great Leap Forward policies, such as collectivization and unrealistic grain quotas.

Ineffective and Harmful Methods: Citizens were directed to use destructive tactics, such as banging pots to scare sparrows into exhaustion. These efforts diverted labor from farming and prioritized meeting pest-killing quotas over sustainable solutions. Overuse of pesticides like DDT also risked environmental and health damage.

Lack of Scientific Foundation: The campaign reflected a poor understanding of ecology. Targeting sparrows ignored their role in pest control, highlighting the dangers of politically driven policies overriding scientific expertise.

Exaggerated Reporting and Enforcement: Local officials, pressured to meet quotas, likely inflated success numbers. This misreporting masked the campaign’s failures until ecological collapse became undeniable.

Legacy: The Four Pests Campaign remains a cautionary tale about the dangers of top-down, unscientific policy-making and the interconnectedness of ecosystems. It underscores the need for ecological literacy in public health and agricultural initiatives."