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.

Elephants spray tourists with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, about 80 km (50 miles) north of Bangkok, April 9, 2014. (Photo by Rungroj Yongrit/EFE)

A girl stands against strong wind caused by Typhoon Mangkhut at a pier on the waterfront of Victoria Habour Hong Kong, Sunday, September 16, 2018. Hong Kong and southern China hunkered down as strong winds and heavy rain from Typhoon Mangkhut lash the densely populated coast. The biggest storm of the year left at least 28 dead from landslides and drownings as it sliced through the northern Philippines. (Photo by Vincent Yu/AP Photo)

A seagull who turned bright orange after he plunged into a vat of chicken tikka masala in Beckford, England on June 9, 2016. The bird fell into a container of the food while trying to scavenge a piece of meat from a food factory bin in Wales. (Photo by Vale Wildlife Hospital/PA Wire)

This undated photo provided by the U.S. Fish and Wildlife Service shows two island foxes in Channel Islands National Park, Calif. Three fox subspecies native to California's Channel Islands were removed from the list of endangered species Thursday, August 11, 2016, in what federal officials have called the fastest recovery of any mammal listed under the Endangered Species Act. (Photo by Chuck Graham/U.S. Fish and Wildlife Service via AP Photo)

It’s time to start watching for Comet PANSTARRS, one of two comets to get excited about in 2013. Photo: This image provided by NASA shoaws the comet PANSTARRS as seen from Mount Dale, Western Australia on March 5, 2013. According to NASA on March 10, it will make its closest approach to the sun about 28 million miles (45 million kilometers) away. As it continues its nightly trek across the sky, the comet may get lost in the sun's glare but should return and be visible to the naked eye by March 12. (Photo by AP Photo/NASA)

A view of a turtle during an event at the Ministry of Environment in Phnom Penh, Cambodia, 24 June 2020. A Cambodian woman recently bought endangered Royal Turtles from local villagers and gave them to Ministry of Environment. (Photo by Kith Serey/EPA/EFE)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)