People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)

An Indian Runner duck searches for food on a snow-covered meadow in Aitrang, southern Germany, Wednesday. April 19, 2017. (Photo by Karl-Josef Hildenbrand/DPA via AP Photo)

A government awareness poster for wearing surgical masks is seen reflected and upside-down in the Dambovita river in Bucharest, Romania, 19 November 2020. The poster, depicting a man wearing a surgical mask, reads: “I WEAR A MASK BECAUSE I KNOW THAT ONLY TOGETHER WE WILL SUCCEED!”. As the number of COVID-19 infections increased, authorities decided that wearing a protective mask should become mandatory at all times in all public places. (Photo by Robert Ghement/EPA/EFE)

Policemen escort a Femen activist who broke into a rally of Franco's dictatorship regimen followers in Madrid, Spain, 28 March 2021. (Photo by Zipi/EPA/EFE)

Twenty-year-old women draped in traditional kimonos gather for their “Coming-of-Age Day” ceremony at the Tokyo Disneyland in Urayasu, eastern suburb of Tokyo on January 13, 2020. (Photo by Kazuhiro Nogi/AFP Photo)

Actress/Model Emily Ratajkowski's celebrates her 25th birthday at the private residence of Absolut Elyx CEO Jonas Tahlin on June 10, 2016 in Los Angeles, California. (Photo by Rachel Murray/Getty Images for Absolut Elyx)

June 21: “World War Z”. Brad Pitt battles zombie apocalypse in $170 million film by “Quantum of Solace” director Marc Forster. This publicity photo released by Paramount Pictures shows, center, Brad Pitt as Gerald Lane in a scene from the film, “World War Z”, from Paramount Pictures and Skydance Productions in association with Hemisphere Media Capital and GK Films. (Photo by Jaap Buitendijk/AP Photo/Paramount Pictures)

“Winter shapes, Moscow river”. Moscow river at this part is never covered by ice. When the temperature is very low it's possible to see a strong fog. Morning light and pipes of the oli factory creates a fantastic landscape. Photo location: Moscow, Russia. (Photo and caption by Sergey Rumyantsev/National Geographic Photo Contest)