Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

Pamukkale, Turkey, is home to these terrace pools, formed by the build-up of carbonate mineral from the warm water flowing from the thermal springs above. (Photo by Image Courtesy of Jennifer Hayes/Getty Images)

This green-skinned trio were happy to pose for the camera – with one little frog smiling happily for its close up. The three Reinwardt's Flying Frog, commonly known as the black webbed tree frog or the green flying frog, were spotted playing in a tree by photographer Hendy Mp. The 25-year-old who saw the frogs near his home in Sambas, Kalimantan Barat, in Indonesia, said they reminded him of three brothers playing together. (Photo by Hendy Mp/SOLENT News)

Chinese aids activists hand out condoms in a subway train in Wuhan, central China's Hubei province on December 1, 2014. The World Health Organization issued a call to action to China on December 1, 2014 over HIV/AIDS as government figures said nearly half a million people are living with the disease or its precursor, with hundreds of thousands more thought to be undiagnosed. (Photo by AFP Photo)

A South Sudanese People Liberation Army (SPLA) soldier patrols the streets in Malakal on January 21, 2014. (Photo by Harrison Ngethi/AFP Photo)

A visitor to ''The Cult of Beauty: The Aesthetic Movement 1860-1900'' exhibition at The V&A Museum looks at sculptures by Thornycroft (L) and Watts on March 30, 2011 in London, England. This exhibition brings together for the first time many masterpieces in painting, sculpture, design and furniture as well as fashion and literature and runs from April 2nd to July 17th 2011.

US model Bella Hadid poses as she arrives for the screening of the film “Rocketman” at the 72nd edition of the Cannes Film Festival in Cannes, southern France, on May 16, 2019. (Photo by Antonin Thuillier/AFP Photo)

Participants of the the goth festival “Wave Gothic Festival” walk in fancy costumes along the festival area in Leipzig, central Germany, Saturday, May 23, 2015. About 20,000 members of the scene are expected to attend one of the world's largest gothic and “dark” culture festivals until May 25, 2015. (Photo by Jens Meyer/AP Photo)