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)

People run in panic after a coalition airstrike hit Islamic State fighters positions in Tahrir neighbourhood of Mosul, Iraq, November 17, 2016. (Photo by Goran Tomasevic/Reuters)

A barking-mad designer, Leah Workman, has launched a range of wigs that turn pets into pop princesses including Katy Perry, Lady Gaga, and even Marilyn Monroe. Photo: Lady Gaga wig. (Photo by Cushzilla/BNPS)

The more representative dogs from every country photographed wearing the uniform of their football national team for Life on White

“Kilauea Rules”. The most extreme place we put ours kayakers to paddle till now. Photo location: Big Island, Hawaii. (Photo and caption by Alexandre Socci/National Geographic Photo Contest)

A man holds onto a tree by the seashore (possibly along the Shore Parkway Greenway) against severe winds during Hurricane Carol's assault on the Northeastern seaboard, Brooklyn, New York, August 31, 1954. (Photo by Hulton Archive/Getty Images)

Participants take part in a high-heel race at a Gay Pride party in the central neighborhood of Chueca in Madrid on July 3, 2014. (Photo by Gerard Julien/AFP Photo)