An African giant pouched rat sniffs for traces of landmine explosives at APOPO's training facility in Morogoro on June 17, 2016. APOPO trains the rats to detect both tuberculosis and landmines at its facility. Every year landmines kill or maim thousands of people worldwide. The trained rats sniff for explosive and so are able to detect the presence of landmines far faster than conventional methods which involve metal detection. (Photo by Carl De Souza/AFP Photo)

Wales' Gemma Frizelle competes in the Team Final and Individual Qualification Sub Division 2 at the Coomera Indoor Sports Centre during day seven of the 2018 Commonwealth Games in the Gold Coast, Australia on April 11, 2018. (Photo by David Gray/Reuters)

A woman smokes marijuana during a Global March for Marijuana in Medellin, Colombia, May 5, 2018. The annual Global Marijuana March is taking place in over 100 cities across the world in an effort to raise awareness of the benefits of medical cannabis and to call for the legalization of marijuana. (Photo by Fredy Builes/Reuters)

German troops in Stalingrad, USSR. September 10, 1942. (Photo by TASS)

Ex-Pussycat Dolls singer Nicole Scherzinger and The Cuban Brothers perform at the de Grisogono party during the 71st annual Cannes Film Festival at Villa des Oliviers on May 15, 2018 in Cap d'Antibes, France. (Photo by Goff Photos)

People dressed as a dancing devils with giant mask dance on a street, during a traditional celebration in Naiguata, Venezuela, Thursday, May 31, 2018. Carrying in their hands striking masks mostly animals and sea monsters, hundreds of men, women and children went out to dance frantically as possessed by evil spirits in an ancient ritual known as Dancing Devils of Naiguata, the unorthodox way of the coastal towns of Venezuela to venerate God during the celebrations of Corpus Christi. (Photo by Ariana Cubillos/AP Photo)

An Afghan hunter shoots at a duck in Laghman province, Afghanistan on May 30, 2018. (Photo by Reuters/Parwiz)

New program of Munich's Krone Circus performed by two American artists “The Carmenas” during a press conference in Munich, Germany on January 10, 1962, while sitting in a coffee-house. (Photo by Heinrich Sanden Sr./AP Photo)