The first gender-neutral restroom in the Los Angeles school district is seen at Santee Education Complex high school in Los Angeles, California, U.S., April 18, 2016. (Photo by Lucy Nicholson/Reuters)

Artists perform during the opening show directed by German director Volker Hesse, on the opening day of the Gotthard rail tunnel, at the fairground Rynaecht at the northern portal in Erstfeld, Switzerland, Wednesday, June 1, 2016. The construction of the 57 kilometer long tunnel began in 1999, the breakthrough was in 2010. After the official opening on June 1, the commercial operation will start in December 2016. (Photo by Ruben Sprich\Pool Photo via AP Photo)

Отава Ё – Яблочко (Otava Yo – Yablochko; Russian: Яблочко, “Little Apple”). Yablochko is a Russian folk song of chastushka style and dance, traditionally presented as sailors' dance. The choreographed version of the dance first appeared in the 1926 Reinhold Glière ballet The Red Poppy and from there is known in the West as the Russian Sailors Dance.

Dancers from Xinjiang delegation perform during the Opening Ceremony for the 9th National Traditional Games of Ethnic Minorities of the People's Republic of China on September 10, 2011 in Guiyang, China. (Photo by Feng Li/Getty Images)

“Sperm whale opening it's huge mouth, Ogasawara Islands, Japan. Sperm whales are the biggest carnivorous animals on the planet. Each teeth in the mouth of adult specimen weights more than 1 kilogram. Interestingly enough that modern marine biologists believe that these teeth despite being fearsome play little role in capturing and eating giant squid – with their main function being mainly ritual aggression between males!”. (Photo by Alexander Safonov)

A little red flying fox dips a toe in a lake at the mouth of Katherine gorge in the Northern Territory, Nitmiluk national park, Australia on September 20, 2017. (Photo by Glenn Campbell/AAP)

These unique photos capture the moment a boy has his teeth picked clean by amazing underwater shrimp. These fascinating creatures spend their lives diving inside the mouths of fish to remove the parasites that lurk there. Russell Laman imitated the behaviour of the surrounding fish swarm to entice the cleaner shrimp into his mouth whilst snorkelling with his father Tim Laman in Bali, Indonesia. The 13-year-old queued with the waiting fish and then opened his mouth when the shrimps came near. (Photo by Tim Laman/Caters News)