Riot police stood by the gates of parliament in Nairobi, Kenya, Tuesday, May 14, 2013, during a demonstration against members of parliament who demanded higher wages. Demonstrators released two dozen piglets and poured blood on the pavement to protest the demands for a wage hike. (Photo by Carl de Souza/AFP Photo)

A lioness bares its teeth inside an enclosure after a raid at a zoo-like house on the outskirts of Bangkok, Thailand Monday, June 10, 2013. Thai police and forestry officials searched and seized a number of imported and endangered animals including 14 lions from Africa and arrested the house's owner. (Photo by Apichart Weerawong/AP Photo)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

An installation of Canadian artists Caitlind Brown and Wayne Garrett is displayed during the Lumina Light Festival in Cascais September 14, 2014. Lumina Light Festival shows artworks of artists from several countries, which are displayed during a tour around Cascais. (Photo by Rafael Marchante/Reuters)

A man (2nd L) takes pictures as visitors run away from a wave caused by a tidal bore which surged past a barrier on the banks of Qiantang River, in Hangzhou, Zhejiang province August 14, 2014. (Photo by Reuters/Stringer)

A woman sells Cuban Communist Party (PCC) official newspaper Granma with a picture of former Cuba's President Fidel Castro at the front page, at the main touristic road in Havana, Cuba, September 14, 2016. (Photo by Alexandre Meneghini/Reuters)

Crowds look on as the super moon rises behind the Fremantle War Memorial at Monument Hill on November 14, 2016 in Fremantle, Australia. A super moon occurs when a full moon passes closes to earth than usual, with the November 14th moon expected to be closer than it has been in over 70 years. (Photo by Paul Kane/Getty Images)

A wax figure of President William Howard Taft is seated in the front seat with his detached head in the back after it was purchased from an auction of the Hall of Presidents Museum, which closed in November, in Gettysburg, Pennsylvania, U.S. January 14, 2017. (Photo by Mark Makela/Reuters)