In 1958 Chairman Mao Tse-tung decided that sparrows were eating too much of China's grain harvest and so he declared a national war on the birds.
Over the next several months, people all over China banged pots and pans to scare sparrows and keep them flying around until they collapsed of exhaustion. One 16-year-old buy, Yang Seh-mun, became a national hero by taking a more direct approach. He killed 20,000 sparrows by climbing up to their night roosting sites and strangling the birds he found there.
Millions of birds were killed across China and their carcasses were sometimes paraded through the streets.I
The "war" was a success and the year's grain harvest was significantly increased.
However, the Chinese had ignored the fact that nature operates by a system of checks and balances. The absence of sparrows meant that there were no longer enough birds in the country to keep insect populations in check. As a result, the 1959 grain crops were devastated by a plague of locusts - and the ensuing food shortage killed some 10 million Chinese.