A group of young men use a selfie stick to take a picture of themselves in shallow waters known as the first cataract of the River Nile outside Khartoum, Sudan, May 22, 2015. In Sudan, which faces insurgences in the western region of Darfur and along its border with breakaway South Sudan, as well as double-digit inflation and high unemployment, life goes on for young people in the capital Khartoum. (Photo by Mohamed Nureldin Abdallah/Reuters)

In this June 23, 2015 photo, Ashaninka Indian beauty contestants pose for a photo with members of a visiting music group, hired to perform during the annual founding anniversary festivities, in Otari Nativo, Pichari, Peru. The contestants wear the simple brown dresses of the Ashaninka woman, their faces dotted in a traditional design with a red dye extracted from a spice called achiote. (Photo by Rodrigo Abd/AP Photo)

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 group of dancers pose for a photo before their performance at the Nueva Esperanza cemetery in the shantytown Villa Maria, in Lima, Peru, Tuesday, November 1, 2016, as part of the Day of the Dead festivities. The holiday honors the deceased and coincides with All Saints Day, and All Souls Day celebrated on Nov. 1 and 2. Dancing, drinking alcohol, and eating with the deceased are part of Day of the Dead celebrations. (Photo by Martin Mejia/AP Photo)

Iraqi army soldiers fire mortars against the Islamic State militants, at Shahrazad village 2 miles (3 kilometers) east of Mosul, Iraq, Monday, November 14, 2016. A suicide bombing in Iraq targeted the Shiite sacred city of Karbala on Monday, killing at least six civilians, the latest attempt by the Islamic State group to distract from the government forces' offensive on the IS-held northern city of Mosul. (Photo by Hussein Malla/AP Photo)

In this November 7, 2016 photo, “El Menor”, a member of “Los Cainos” self-defense group formed by the Marval fishing family, holds a homemade gun before starting a night patrol to help protect fishermen from pirate attacks in Punta de Araya, Sucre state, Venezuela. Pirates are terrorizing the coastal state of Sucre, once home to the world's fourth-largest tuna fleet and a thriving fishing industry. (Photo by Rodrigo Abd/AP Photo)

Kayaks, 7, poses for a picture holding toy gun in a camp where Christians displaced by Islamic State militants are living, in Irbil, Iraq, Friday, December 23, 2016. Iraq’s Christians are marking the holiday in his camp for displaced people with a sense of worry and despair, unable to return to their towns they were forced to flee two years ago by the Islamic State group’s onslaught. (Photo by Manu Brabo/AP Photo)

Yang Juan, an employee at Goopal Group, takes a nap in her seat after lunch, in Beijing, China, April 21, 2016. Office workers sleeping on the job is a common sight in China, where a surplus of cheap labour can lead to downtime at work. But in China's technology sector, where business is growing faster than many start-up firms can hire new staff, workers burn the midnight oil to meet deadlines and compete with their rivals. Some companies provide sleeping areas and beds for workers to rest during late nights. (Photo by Jason Lee/Reuters)