Fireworks explode over the Kremlin in Red Square which was blocked by police during New Year celebrations in Moscow, Russia, Sunday, January 1, 2017. New Year's Eve is Russia's major gift-giving holiday, and big Russian cities were awash in festive lights and decorations. (Photo by Alexander Zemlianichenko Jr./AP Photo)

A student aims a stick of wood at Bolivarian National Police officers during clashes outside the Central University in Caracas, Venezuela, Thursday, June 9, 2016. Students had planned to march from Venezuela's top university to elections headquarters, but hundreds of police in riot gear blocked the way. Students covered their faces with Venezuelan flags and threw bottles, stones and sticks while police lobbed tear gas. (Photo by Fernando Llano/AP Photo)

The main church in the town of San Damian Texoloc, Mexico stands in front of the Popocatepetl volcano as is spews ash and vapor early Tuesday, July 9, 2013. Last Saturday, Mexico's National Center for Disaster Prevention raised the volcano alert from Stage 2 Yellow to Stage 3 Yellow, the final step before a Red alert, when possible evacuations could be ordered after the Popocatepetl volcano spit out a cloud of ash and vapor 2 miles (3 kilometers) high over several days of eruptions. (Photo by J. Guadalupe Perez/AP Photo)

Is it a leaf? Is it tree bark? No, it’s the Satanic leaf-tailed gecko. Cleverly disguised as a rotting leaf, Madagascar’s camouflage king has red eyes, pointy horns and a taste for night hunting: it’s nature’s most devilish deceiver. The twisted body and veiny skin echo the detail of a dry leaf, which ensures the gecko blends in with its forest home. The mottled tail appears to have sections missing, as though it has withered over time. This mini-monster epitomises survival of the fittest, having adapted gradually to become today’s extraordinary leaf impersonator. (Photo by Thomas Marent/ARDEA)

A policeman kick in the door of a residence next to the Black Panther headquarters in New Orleans as they moved in following a shootout, September 15, 1970. Other heavily armed policemen stand at ready. (Photo by Jack Thornell/AP Photo)

A Venezuelan Bolivarian National Police officer fires tear gas towards demonstrators during a protest in Caracas, Venezuela, Monday, April 10, 2017. Thousands of people in Venezuela's capital are protesting against the government of President Nicolas Maduro, demanding new elections and vowing to stay in the streets during the usually quiet Easter Week. (Photo by Fernando Llano/AP Photo)

The battle by Jose Garcia, US. Category: bird behaviour. A great white heron (Ardea herodias occidentalis) fighting a green snake in the Florida Everglades. The fight lasted for nearly 20 minutes with the heron having to release its prey. (Photo by Jose Garcia/2017 Bird Photographer of the Year Awards)

Archive: A group of people dressed as Santa Claus wait for the bus on December 1960, London, England. (Photo by Keystone-France/Gamma-Keystone via Getty Images) Modern Day: Passengers wait for busses in Holborn on November 24, 2017 in London, England. (Photo by Chris J. Ratcliffe/Getty Images)