Woman and man playing domination games in bed. (Photo by NDAB Creativity/Rex Features/Shutterstock)

A mother and her daughter paddle during a Stand Up Paddle (SUP) race of the Alpine Lakes Tour, on Europe's biggest underground lake, in St-Leonard, Switzerland, March 10, 2018. SUP is an offshoot of surfing that originated in Hawaii. Unlike traditional surfing where the rider sits until a wave comes, stand up paddle boarders stand on their boards and use a paddle to propel themselves through the water. (Photo by Denis Balibouse/Reuters)

A man crosses from a pirogue to another pirogue during the annual boat regatta in Yauri, Kebbi State, on February 15, 2025. The regatta festival started about 200 years ago as a display of naval strength of the Gungu people, where the Gungu warriors annually attacked dangerous hippopotamus that were destroying farmlands. Warriors would board various sizes of canoes with different types of weapons to attack the animal on the River Niger. This required expertise in canoe paddling and naval warfare. It also served as training exercise for upcoming Gungu warriors. (Photo by Toyin Adedokun/AFP Photo)

Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

“Elat’ma, the Ryazan Oblast region of Russia. This small town is only 300 kilometers (186 miles) from modern Moscow but remains 60 years in the past, dominated by the spirit of socialism. The air of the communist ‘50s can be seen in the town’s architecture, celebrations and other occurrences. But neither its beauty nor its ties to a socialist past brought photographer Anastasia Rudenko to this village. Elat’ma is unique in that it functions as a town for mentally disabled people”. – Michelle Cohan via CNN. (Photo by Anastasia Rudenko)

Kira Walkenhorst of Germany (L) signals as Doaa Elghobashy of Egypt (R) watches during the women's Beach Volleyball preliminary pool D game between Ludwig/Walkenhors of Germany and Elghobashy/Nada of Egypt the Rio 2016 Olympic Games at the Beach Volleyball Arena on Copacabana Beach in Rio de Janeiro, Brazil, 07 August 2016. (Photo by Antonio Lacerda/ANSA)

Humanoid robots fight during a kickboxing match on day two of the 2025 World Humanoid Robot Games at National Speed Skating Oval on August 16, 2025 in Beijing, China. The 2025 World Humanoid Robot Games (WHRG) will be held from August 14 to 17 in Beijing's National Speed Skating Oval, bringing together 280 teams from 16 countries across five continents. (Photo by Lintao Zhang/Getty Images)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)