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)

These macro images by Alejandro Santillana are being showcased in the Insects Unlocked project at the University of Texas at Austin. Here: A female sweat bee. (Photo by Alejandro Santillana/Insects Unlocked/Cover Images)

Anfisa, a twelve-year-old female chimpanzee, picks its nose at the Royev Ruchey Zoo in a suburb of the Siberian city of Krasnoyarsk, Russia on October 18, 2017. (Photo by Ilya Naymushin/Reuters)

Afghan female police cadets are seen during their graduation ceremony at Sivas Police Vocational Center Directorate in Sivas, Turkey on March 13, 2018. (Photo by Serhat Zafer/Anadolu Agency/Getty Images)

Liu Yang, China's first female astronaut, waves during a departure ceremony at Jiuquan Satellite Launch Center, on June 16, 2012. (Photo by Jason Lee/Reuters via The Atlantic)

Female North Korean soldiers parade to mark the 60th anniversary of the signing of a truce in the 1950-1953 Korean War at Kim Il-sung Square, in Pyongyang. (Photo by Jason Lee/Reuters)