In this Thursday, April 11, 2013 photo, North Korean female soldiers stand watch on the river bank of the North Korean town of Sinuiju, opposite to the Chinese border city of Dandong. (Photo by AP Photo)

In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)

A newborn baby giraffe shows its tongue at the Planckendael zoo in Mechelen, 25 kilometers North of Brussels, Tuesday, February 18, 2014. The calf was born on Valentines day, February 14, and has a heart shaped spot on the hip. (Photo by Yves Logghe/AP Photo)

Monks dressed as Tibetan Buddhism characters attend a religious ceremony, known as “Da Gui” or beating ghost, to celebrate the upcoming Tibetan New Year which starts on March 1 at Yonghegong Lama Temple, in Beijing February 28, 2014. This Tibetan ceremony is held annually at the end of the first lunar month with mask dancing to expel ghosts, according to a press release. (Photo by Jason Lee/Reuters)

A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)

In this photo illustration a plastic carrier bag is blown along the road by the wind on March 4, 2008 in Birmingham, England. (Photo illustration by Christopher Furlong/Getty Images)

A model falls and gets help back to her feet during the fashion show for the Givenchy Spring 2016 collection at Fashion Week on, Friday, September 11, 2015, in New York. (Photo by Bebeto Matthews/AP Photo)

A tourist stands on the shore of a private beach in Naama Bay, Sharm el-Sheikh, south Sinai, Egypt, Sunday, November 8, 2015. Britain's foreign secretary says airport security in many cities will need to be overhauled if it is confirmed the Russian plane crash in the Sinai was caused by a bomb planted by the Islamic State group or someone inspired by the militants. (Photo by Vinciane Jacquet/AP Photo)