Andreyka, a 10-month-old female bear cub, plays with Rommi, an Alaskan malamute, at the Siberian Zoo in the settlement of Listvyanka, Irkutsk Region, Russia on December 9, 2020. The bear cub, which was found in a weak condition earlier this year, now play-fights with the Alaskan malamute, who adopted her and has seen three generations of bear cubs brought up in the Siberian zoo and released back into the wild. (Photo by Yuri Novikov/Reuters)

A deer walks across a pedestrian crossing in Nara, Japan, Thursday, March 19, 2020. More than 1,000 deer roam free in the ancient capital city of Japan. Despite the town's tourism decline, these wild animals are doing just fine without treats from tourists, according to a deer protection group. (Photo by Jae C. Hong/AP Photo)

Purev and Buyantogtokh enjoy the warmth of the fire in the snow in Altai Mountains, Mongolia, September 2016. Navigate the snowy wilds of Mongolia with this nomadic reindeer herding family. Photographer Joel Santos dived 1000km into the depths of Northern Mongolia to visit the Ganbaa family near Khovsgol Lake. (Photo by Joel Santos/Barcroft Images)

Snowdrops that are already in early bloom are seen at Rococo Gardens in Painswick on January 12, 2012 near Stroud, England. The unseasonably warm weather has seen wild flowers burst into bloom months ahead of schedule. However weather forecasters are warning of a return to colder temperatures later this week as a widespread frost is expected tonight. (Photo by Matt Cardy/Getty Images)

Chincoteague Ponies swim across Assateague Channel in a heavy downpour on Wednesday, July 24, 2013 during the 88th Annual Chincoteague Pony Swim. A portion of the herd will be auctioned on Thursday. (Photo by Jay Diem/Eastern Shore News)

Talini (R), a 9-month old 160-pound polar bear cub, swims with her mother Barle at the Detroit Zoo's Artic Ring of Life exhibit August 25, 2005 in Royal Oak, Michigan. Talini's birth was the first polar bear birth at the Detroit Zoo in fifteen years. Her mother Barle was wild born and was rescued by the Detroit Zoo from a circus in Puerto Rico in 2002. (Photo by Bill Pugliano/Getty Images)

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.