Female Kurdish Peshmerga take part their graduation ceremony at a police academy in Zakho district of the Dohuk Governorate of the Iraqi Kurdistan province, Iraq March 30, 2016. (Photo by Ari Jalal/Reuters)

Two guards perform an execution in China, one holding the gun, the other holding a mask over the victim's face. (Photo by General Photographic Agency/Getty Images). Circa 1925

An undated handout picture released on January 10, 2017 by the Issekinicho publishing house shows an inter- species sexual behaviour between a male Japanese macaque and female sika deer, in Yakushima Scientists revealed on January 10, 2017 the “highly unusual” behaviour of a male monkey filmed trying to have sеx with female deer in Japan – a rare case of inter- species nookie. (Photo by Editions Issekinicho/AFP Photo)

A young male fiddler crab is dwarfed by an older male of the same species, looming behind it at Morua estuary, in the Gulf of California, Mexico on January 4, 2022. Whereas female fiddler crabs have small claws of equal sizes, the males’ pincers can vary in size, with the small one used to pick up food and the larger to impress females. (Photo by Claudio Contreras/Solent News)

A soldier stands guard on the aircraft park of the Pyongyang Airport on April 3, 2011 in Pyongyang, North Korea. Pyongyang is the capital city of North Korea and the population is about 2,500,000.

Alejandro Simon of Spain prepares to serve during their Preliminary Phase Pool E match against Canada during the VISA FIVB Beach Volleyball International at Horse Guards Parade on August 10, 2011 in London, England. (Photo by Scott Heavey/Getty Images)

An elephant bull charges a female hippopotamus as her calf scampers to safety, in Erindi Private Game Reserve in Windhoek, Namibia. (Photo by Rian van Schalkwyk/Barcroft Media)

A Syrian Democratic Forces (SDF) female fighter adjusts a mortar in northern Deir al-Zor province ahead of an offensive against Islamic State militants, Syria February 21, 2017. (Photo by Rodi Said/Reuters)