David Sharp, an engineer with Lockheed Martin, displays the “Samurai Flyer”, an aviation design inspired by the maple seed, during the Association for Unmanned Vehicle Systems International Conference August 16, 2011 in Washington, DC. Lockheed Martin unveiled the new design and demonstrated vertical takeoff and landing, stable hover, and on-board video streaming of the aircraft during their demonstration. (Photo by Win McNamee/Getty Images)

Visitors look on as a man (front) inserts two live snakes through his nose and mouth during a performance at an amusement park to celebrate the 65th anniversary of the founding of the People's Republic of China and the 7-day national day holiday, in Jinhua, Zhejiang province October 1, 2014. (Photo by Reuters/Stringer)

A woman plays around as she walks across a glass-bottomed suspension bridge in a scenic zone in Pingjiang county in southern China's Hunan province Thursday, September 24, 2015. The bridge, 300 meters (984 feet) long and 180 meters (590 feet), opened to visitors on Thursday for the first time since its conversion from a regular suspension bridge was completed. (Photo by Chinatopix Via AP Photo)

A flight deck crew prepares to launch a F18 Super Hornet from the deck of the USS Eisenhower off the coast of Virginia, December 10, 2015 in the Atlantic Ocean. US Defense Secretary Ash Carter visited the carrier with India's Minister of Defense Manohar Parrikar to demonstrate US Navy aircraft carrier flight operations. (Photo by Mark Wilson/Getty Images)

Medical residents, who removed their clothes to protest against working conditions, take part on a protest during a strike in Barcelona, Spain, Tuesday, October 20, 2020. Regional authorities across Spain continue to tighten restrictions against a sharp resurgence of coronavirus infections that is bringing the country’s cumulative caseload close to one million infections, the highest tally in western Europe. (Photo by Emilio Morenatti/AP Photo)

A Catholic faithful fancy dressed as a “talciguin” -character of the local folklore- takes part in the celebration of an ancient local tradition that marks the start of Holy Week, in Texistepeque, some 80 km west of San Salvador, on April 15, 2019. Talciguines are devils who “lash” Catholic faithfuls to cleanse their sins. (Photo by Marvin Recinos/AFP Photo)

In this undated photo provided on Monday, November 25, 2019, by the North Korean government, North Korean leader Kim Jong Un, center, poses as he inspects a women's company under Unit 5492 of the Korean People's Army in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. (Photo by Korean Central News Agency/Korea News Service via AP Photo)

A member of the public wears a pandemic face mask ahead of the prime minister announcing the government's Covid-19 winter strategy on September 13, 2021 in Manchester, England. Tomorrow, British Prime Minister Boris Johnson will set out his plan to manage Covid-19 through the winter, including what actions would need to be taken if the NHS hospital system were at risk of being overwhelmed. (Photo by Christopher Furlong/Getty Images)