A traffic policeman hides a rose behind his back before giving it to a female driver ahead of International Women's Day in Ryazan, Russia on March 7, 2017. (Photo by Alexander Ryumin/TASS via Getty Images)

An Afghan policeman stands guard in front of a French restaurant “Le Jardin” after a suicide attack in Kabul, Afghanistan January 2, 2016. A suicide attack on a French restaurant in the Afghan capital Kabul on Friday killed a 12-year-old boy and wounded more than a dozen other people, officials said. (Photo by Mohammad Ismail/Reuters)

Secret arrive during the 1st Gaon Chart K-POP Awards at Blue Square on February 22, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Victoria's Secret Angel Martha Hunt celebrates the 2015 What Is s*xy? List in San Diego on September 26, 2015 in San Diego, California. (Photo by Joe Scarnici/Getty Images for Victoria's Secret)

Victoria's Secret model Adriana Lima poses with her Madame Tussaud's wax likeness at a reveal event at the Victoria’s Secret store in Herald Square in the Manhattan borough of New York November 30, 2015. (Photo by Brendan McDermid/Reuters)

An Indian policeman wearing a virus themed helmet rides on a horse during an awareness rally aimed at preventing the spread of new coronavirus in Hyderabad, India, Thursday, April 2, 2020. (Photo by Mahesh Kumar A./AP Photo)

A demonstrator holds a rose and shouts slogans in front of a riot policeman during an unauthorized march called by secondary students to protest against government education reforms in Valparaiso, Chile, May 26, 2016. (Photo by Rodrigo Garrido/Reuters)

Only after World War II did the secret spill: Ōkunoshima, located in the Inland Sea of Japan between Hiroshima and Shikoku, was the top-secret site for manufacturing chemical warfare. When the factories were closed down, a number of exotic wild rabbits were seen freely roaming the island. They were assumed to have been the test subjects for the chemical weapons, which the military failed to eradicate when the factory was demolished.