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.

Reflected in the rearview mirror, Jose Collantes gets a hug from daughter Kehity while they're stopped at a red light, as Jose drives his five-year-old home from a playdate in Santiago, Chile, Sunday, September 6, 2020, three months after they lost his wife, her mother, to COVID-19. Their case highlights how COVID-19 deaths the world over are often the beginning of a new personal journey for those affected. (Photo by Esteban Felix/AP Photo)

Iranian girls wearing face masks walk in Tehran, Iran, 02 November 2020. According to the Iranian Health ministry, Iran reported its highest daily COVID-19 death toll and infections by announcing 440 deaths and 8,289 new infections in past 24 hours in what appears to be a third wave of COVID-19 outbreak. (Photo by Abedin Taherkenareh/EPA/EFE)

A resident receives a dose of Pfizer BioNTech COVID-19 vaccine at a rural village on December 01, 2021 in Aringay, La Union province, Philippines. The Philippines is rushing to vaccinate its population as it mulls making COVID-19 vaccination mandatory and amid the looming threat of the Omicron variant of the coronavirus. The country, which has just approved booster shots for its adult population, launched a three-day national vaccination holiday on November 29 to December 1 with the goal of vaccinating at least nine million additional people. (Photo by Ezra Acayan/Getty Images)

An Iranian woman wearing a face mask walks on a street in Tehran, Iran, 19 October 2020. According to the Iranian Health ministry, Iran reported its highest daily COVID-19 death toll of 337 and 4,251 new infections in past 24 hours as it appears that Iran is in a third wave of COVID-19 outbreak. (Photo by Abedin Taherkenareh/EPA/EFE)

An indigenous man of Mahmeri tribe wearing a costume of Puteri Gunung Ledang character receives a dose of the vaccine against Covid-19 in Banting, near Kuala Lumpur, Malaysia,15 August 2021. Malaysia recorded another 20,670 new Covid-19 cases on 14 August, bringing the cumulative total to 1,384,353 cases. (Photo by Ahmad Yusni/EPA/EFE)

Indian people bang utensils and clap from the balconies of a residential building in Mumbai, India, 22 March 2020. Prime Minister Narendra Modi asks citizens to impose self-curfew to fight Coronavirus COVID-19 and also ask them to clap, bang the bells and utensils at 5pm Indian time to mark of respect and to thank the medical staff and others working 24 hours, during Covid-19 outbreak to keeping the Indians safe. (Photo by Divyakant Solanki/EPA/EFE)

A Thai Buddhist monk prepares to take part in a televised anti-plague prayer at Wat Traimit Temple (Temple of the Golden Buddha) amid lockdown restrictions to contain the spread of the COVID-19 coronavirus in Bangkok on March 25, 2020. The monks at Buddhist temples nationwide chanted the Rattanasoot (Seven Legends) Prayer in unison in a bid to boost public morale amid the epidemic of COVID-19 coronavirus. (Photo by Mladen Antonov/AFP Photo)