Actors perform the living Nativity biblical scenes in Postojna cave in Postojna, Slovenia, December 22, 2015. (Photo by Srdjan Zivulovic/Reuters)

A worker stack bricks on his head at a brick factory in Lalitpur January 12, 2015. (Photo by Navesh Chitrakar/Reuters)

Cats gather in front of a house damaged by shelling in the town of Dokuchayevsk, south of Donetsk, February 12, 2015. (Photo by Maxim Shemetov/Reuters)

A man smokes marijuana during a demonstration in support of the legalization of marijuana in Medellin, May 2, 2015. (Photo by Fredy Builes/Reuters)

A woman is tattooed during the Great British Tattoo Show in Alexandra Palace in north London, Britain May 23, 2015. (Photo by Neil Hall/Reuters)

A contestant poses for a photograph backstage ahead of the Miss Gay Jozi pageant in Johannesburg, May 23, 2015. (Photo by Siphiwe Sibeko/Reuters)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A man makes a mud oven to be used for baking bread at a workshop in Najaf, south of Baghdad, July 23, 2015. (Photo by Alaa Al-Marjani/Reuters)