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)

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

A female honor guard has lipstick applied as they prepare for an official welcoming ceremony outside the Great Hall of the People in Beijing, China on June 11, 2014. (Photo by Jason Lee/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)

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)

Bikini-clad women sit as they operate a 3.6 metre-high custom-made female robot at the “Robot Restaurant” in Kabukicho, one of Tokyo's best known red light districts, August 15, 2012. (Photo by Tokyo Scum Brigade)

A Syrian Democratic Forces (SDF) female fighter's braid is pictured while she is carrying her weapon in Tal Samin village, north of Raqqa city, Syria November 19, 2016. (Photo by Rodi Said/Reuters)