Beijing put the country on red alert in April 1952, charging Americans had secretly been waging germ warfare allegedly dropped infected flies, mosquitoes, spiders, ants, bedbugs, lice, fleas, dragonflies and centipedes over North Korea and Manchuria,. The Americans had also purportedly released contaminated rats, frogs, dead foxes, pork and fish. Enemy planes, it was claimed, had deployed these biological weapons in about a thousand sorties, spreading contagious diseases