Two boys look out from the Mangueira slum towards the Maracana Stadium that is hosting the Rio's 2016 Summer Olympics opening ceremonies, in Rio de Janeiro, Brazil, Friday, August 5, 2016. (Photo by Leo Correa/AP Photo)

“Untitled”. Hong Kong, Wan Chai area, on March 7, 2013. (Photo by Jerry Lee)

This is one boy's amazing picture diary of his pet rodents doing very human tasks. Colin Mclaughlin, from Maryland, USA, has created a hilarious photo collection of his pet guinea pigs, Chester and Sam. (Photo by Colin Mclaughlin/Caters News)

Mara Salvatrucha (MS) gang members show off their weapons in the Las Victorias district of San Salvador. In March 2012, the two largest gangs in El Salvador - the Mara Salvatrucha (MS) and the Barrio 18 (M18) - agreed on a truce following secret negotiations between gang leaders in prison which were mediated by a bishop and a former rebel leader. It is unclear whether the decision was the idea of the gangs themselves or whether they were encouraged by the government. (Photo by Adam Hinton)

Young Ukrainians dance at nightclub House of Meteorologists, May 23, 2014. Sunday's upcoming election in Ukraine has not only exposed the divide between east and west, but between old and young. Unlike their elders, younger people have no memory of Soviet life, and most see themselves as Ukrainian. (Photo by Evelyn Hockstein/The Washington Post)

A Hindu holy man on his way to the annual holy dip at Gangasagar, gestures towards a visitor as he rests at a transit camp in Kolkata, India, Wednesday, January 6, 2016. Thousands of Hindu pilgrims are expected to take the annual holy dip at Gangasagar, where the Ganges River reaches the Bay of Bengal, on the auspicious Makar Sankranti festival day that falls on Jan.14. (Photo by Bikas Das/AP Photo)

Devotees attend the annual voodoo festival in Ouidah January 10, 2016. The national voodoo holiday in the West African country of Benin had a distinctively political accent this year as practitioners from Africa and the Americas gathered on Sunday to offer prayers and sacrifices for peace. Hundreds of followers of the traditional religion gathered in the Atlantic coast town of Ouidah, once an important port in the slave trade, to pray for calm during the tiny country's presidential election scheduled for February. (Photo by Akintunde Akinleye/Reuters)