CHALLOCK, ENGLAND - MARCH 31: Tony Hall walks with his dog through an installation entitled 'Super Kingdom', which hangs in trees in King's Wood as part of the Stour Valley Arts project on March 31, 2011 in Challock, England. The works by artists Bruce Gilchrist and Jo Joelson of 'London Fieldworks' consist of a series of interesting animal habitats, modelled on the palaces of Stalin, Ceauscescu and Mussolini, and offer nesting sites to many native and migrant species. (Photo by Dan Kitwood/Getty Images)

Tibetan monks create an intricate picture made from coloured sand at St. Mungo Museum of Religious Life and Art on November 23, 2011 in Glasgow, Scotland. The monks, from the Panchen Lama's Monastery, are creating a Sand Mandala as part of a Tantric Buddhist ritual, invoking the presence of the Buddha in a design representing the palace of the deities. (Photo by Jeff J Mitchell/Getty Images)

Jane Howorth from national charity the British Hen Welfare Trust holds Liberty the last ex-battery hen to be rehomed on December 29, 2011 in Chulmleigh, England. The rehoming of Liberty signifies the end of the small battery hen cage, which has been phased out and replaced by enriched cages in preparation of the European Union directive banning the smaller cages from January 1, 2012. (Photo by Matt Cardy/Getty Images)

Protesters sit in a cafe during a “SlutWalk” protest, in which several hundred participants march through the centre of Jerusalem, May 13, 2016. The SlutWalk movement began after a Toronto policeman suggested in 2011 that women could avoid sexual assault by not dressing like a “sl*t”. (Photo by Amir Cohen/Reuters)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

Brandy Shelton of Greensboro, North Carolina, “twerks” for a group of bikers on Ocean Boulevard during the 2015 Atlantic Beach Memorial Day BikeFest in Myrtle Beach, South Carolina May 22, 2015. After three people were killed and seven wounded in shootings during 2014 Bikefest, State officials called for an end to the event that draws thousands to the family-friendly beach town.Their efforts were unsuccessful. Bikers returned to Myrtle Beach – just a week after a bloody motorcycle gang shootout in Waco, Texas. But this time authorities are more prepared, with dozens of new surveillance cameras and a police force three times the size of last year's. (Photo by Randall Hill/Reuters)

In this October 6, 1976 file photo a member of a Thai political faction strikes at the lifeless body of a hanged student outside Thammasat University in Bangkok October 6, 1976. For some Thais, the bloody events of October 6, 1976 are still a nightmare. On that day, heavily armed security forces shot up Bangkok's Thammasat University campus and killed scores of students, while right-wing vigilantes captured would-be escapees, subjecting them to ghoulish lynchings. (Photo by Neal Ulevich/AP Photo)