People dressed as zombies take part in a “Zombie Walk” parade in Athens, Greece, February 25, 2017. (Photo by Michalis Karagiannis/Reuters)

This Thursday, January 22, 2015 photo made with a long exposure shows the glow from a Noctiluca scintillans algal bloom along the seashore in Hong Kong. The luminescence, also called Sea Sparkle, is triggered by farm pollution that can be devastating to marine life and local fisheries, according to University of Georgia oceanographer Samantha Joye. Noctiluca itself does not produce neurotoxins like other similar organisms do. But its role as both prey and predator tends can eventually magnify the accumulation of toxins in the food chain, according to R. Eugene Turner at Louisiana State University. (Photo by Kin Cheung/AP Photo)

A ring-tailed lemur is pictured at Zoom Torino, a zoological park in Cumiana near Turin, on April 22, 2015. Zoom Torino is a new immersive zoological park, where animals can be seen without bars or cages, only natural barriers ensure the visit. (Photo by Marco Bertorello/AFP Photo)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

A pole-dancing robot built by British artist Giles Walker performs at a gentlemen's club Monday, January 8, 2018, in Las Vegas. The event was held to coincide with CES International. (Photo by Jae C. Hong/AP Photo)

Richard Gamboa, dressed up as Santa Claus, walks in an alley of the slum Cota 905 during the “Santa en las calles” (Santa in the streets) event donating toys, food, and clothes in Caracas, Venezuela on December 1, 2018. (Photo by Marco Bello/Reuters)

Police run past a burning car as they push protesters back during the “yellow vests” demonstration near the Arc de Triomphe on December 8, 2018 in Paris France. “Yellow Vests” (“Gilet Jaunes” or “Vestes Jaunes”) is a protest movement without political affiliation which was inspired by opposition to a new fuel tax. (Photo by Chris McGrath/Getty Images)

A woman takes part in a “Brave Run” competition in Minsk October 4, 2015. (Photo by Vasily Fedosenko/Reuters)