A group of children run into a fountain on the South Bank on August 1, 2011 in London, England. Temperatures in the capital reached around 27 degress today and are expected to hit 30 degrees by Wednesday. (Photo by Dan Kitwood/Getty Images)

A workman jokes besides a work entitled “Monkey Detonator” by Banksy at Bonhams Auction house on September 16, 2011 in London, England. The piece makes up part of the “Urban Art” sale, and is expected to fetch between £70,000 - £90,000 GBP when it goes under the hammer on September 21, 2001 at Bonhams Auction house in London. (Photo by Dan Kitwood/Getty Images)

A boy looks back while he and another boy play on a Syrian military tank, destroyed during fighting with the Rebels, in the Syrian town of Azaz, on the outskirts of Aleppo, Sunday, September 2, 2012. (Photo by Muhammed Muheisen/AP Photo)

Internally displaced Syrian children stand at the entrance of their makeshift shelter that is an underground cave in Om al-Seer, southern Idlib countryside, Syria December 26, 2015. (Photo by Khalil Ashawi/Reuters)

In this Sunday June 13, 1988 file photo West German police officers arrest an English soccer hooligan who sticks out his tongue. Rioting broke out between some 100 hooligans and the police in downtown Stuttgart, West Germany following the European Soccer Championships match between England and Ireland. England was defeated by Ireland 0-1. (Photo by Kraufmann/AP Photo/File)

Miguel Toribio, 11, puts a pistol belonging to his father into his belt, before demonstrating newly learnt skills from military-style weapons training, to a Reuters journalist in Ayahualtempa, Mexico, February 3, 2020. (Photo by Alexandre Meneghini/Reuters)

8-year-old Fulani boy Suleiman Yusuf drinks milk from a cow belonging to his father cattle near his family's house at Kachia Grazing Reserve, Kaduna State, Nigeria, on April 16, 2019. Kachia Grazing Reserve is an area set aside for the use of Fulani pastoralist and it is intended to be the foci of livestock development. The purpose for the grazing reserves is the settlement of nomadic pastoralists and inducement to sedentarisation through the provision of land for grazing and permanent water as way to avoid conflict. (Photo by Luis Tato/AFP Photo)

Children feeding the birds in this Victorian Christmas greetings card. (Photo by Hulton Archive/Getty Images). Circa 1885