Two men fight in San Jose, Costa Rica, during the Women's Day on March 8, 2014. (Photo by Jeffrey Arguedas/EFE/SIPA Press)

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)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

French actress Frederique Bel arrives for the NRJ Music Awards ceremony at the Festival Palace in Cannes December 13, 2014. (Photo by Eric Gaillard/Reuters)

A view of a stampede is seen during a New Year's celebration on the Bund, a waterfront area in central Shanghai, December 31, 2014. The stampede killed at least 35 people and injured 43 during New Year's Eve celebrations in Shanghai, on the city's famed waterfront tourist strip known as the Bund, authorities said. (Photo by Reuters/Stringer)

This huge male orangutan is having a right old laugh as he squints his eyes and shows his huge teeth. The orangutan, called Bimbo, was relaxing on a platform around 5m high in his enclosure when he broke out into a laugh. But his happy smile soon disappeared when another orangutan came over to see what was going on. Bimbo – the only male in the group of five apes at Leipzig Zoo, in Germany - appears to be laughing in much the same way as a human would. (Photo by Martina Radtke/Solent News)

A sun bear is offered chocolate by a visitor in its enclosure at a zoo in Bandung on January 18, 2017. Animal rights activists on January 18 demanded the closure of an Indonesian zoo after skeletal sun bears were pictured begging for food from visitors and eating their own dung. (Photo by Timur Matahari/AFP Photo)

Ukrainian servicemen patrol near the humanitarian aid center in Avdiivka, Ukraine, Saturday, February 4, 2017. Fighting in eastern Ukraine sharply escalated this week. Ukraine's military said several soldiers were killed over the past day in shelling in eastern Ukraine, where fighting has escalated over the past week. (Photo by Evgeniy Maloletka/AP Photo)