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)

A gibbon drinks from a soft drink bottle, given by a tourist, at a zoo in Kunming, Yunnan province, June 18, 2015. (Photo by Wong Campion/Reuters)

A girl pulls her sister in a discarded basket in the Rashidabad neighborhood of Peshawar, Pakistan October 18, 2015. (Photo by Khuram Parvez/Reuters)

Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

Saraa Mutawkil (R), 18, practises boxing at Al Rabie club in Omdurman May 10, 2016. (Photo by Mohamed Nureldin Abdallah/Reuters)

Girls bath inside a drum on a hot summer day at a field in New Delhi, April 18, 2017. (Photo by Adnan Abidi/Reuters)

An artist draws a tattoo on a woman's arm during a tattoo convention in Ljubljana April 18, 2015. (Photo by Srdjan Zivulovic/Reuters)

People walk on the street in Samara, Russia on July 18, 2017. (Photo by David Mdzinarishvili/Reuters)