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)

Female labourers wearing helmets take a break from laying underground electricity cables in Ahmedabad, India, March 7, 2016. (Photo by Amit Dave/Reuters)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

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)