A woman dressed up as a zombie participates in a zombie walk in Stockholm, Sweden on August 19, 2017. (Photo by Jonathan Nackstrand/AFP Photo)

“Winter Climbing from inside Ben Nevis”. The view from inside the mountain, as a winter climber passes through the cave on Minus Three gully. Photo location: Ben Nevis, Fort William, Scotland. (Photo and caption by Daniel Wildey/National Geographic Photo Contest)

A volunteer operates a remote controlled disinfection robot to disinfect a residental area amid the COVID-19 coronavirus outbreak in Wuhan in China's central Hubei province on March 16, 2020. China tightened quarantine measures for international arrivals on March 16 as the country worries about a rise in imported cases of the deadly coronavirus and anger rages online at how Europe and the United States are handling the pandemic. (Photo by AFP Photo/China Stringer Network)

A member of the wingsuit flyers duo, known as the Soul Flyers, is seen in mid-air as he catches up and flies into the open door of Pilatus Porter plane, piloted by Philippe Bouvier, after B.A.S.E. jumping off the Jungfrau mountain, 4158 meters, in Lauterbrunnen, Switzerland, October 13, 2017. French athletes Fred Fugen and Vince Reffet had 2.45 minutes and a free fall distance of 3200 meters to complete their project “Door In The Sky”, coordinated by Yves Rossy know as the “Jetman”. (Photo by Thibault Gachet/Reuters)

A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)

A fellow officer comes to the aid of injured patrolman C.V. Satt, who was pelted with rocks and beer bottles during a clash between police and relief demonstrators in Denver September 23, 1935. (Photo by Henry G. Eisenhand/AP Photo)

Fox cubs venture out from their den under a popular boardwalk alongside Lake Ontario during the global outbreak of the coronavirus disease (COVID-19), in Toronto, Ontario, Canada on April 22, 2020. (Photo by Carlos Osorio/Reuters)

A four-legged robot dog called SPOT patrols a park as it undergoes testing to be deployed as a safe distancing ambassador, following the coronavirus disease (COVID-19) outbreak, in Singapore on May 8, 2020. (Photo by Edgar Su/Reuters)