A radio-controlled flying witch makes a test flight past a moon setting into clouds along the pacific ocean in Carlsbad, California October 8, 2014. Reuters was invited to photograph the testing of the life sized device by inventor Otto Dieffenbach lll. (Photo by Mike Blake/Reuters)

A partially frozen Niagara Falls is seen on the American side lit by lights during sub freezing temperatures in Niagara Falls, Ontario March 3, 2014. (Photo by Mark Blinch/Reuters)

Armed forces veteran Frank Simpson at the Portico library being camouflaged by body artist Carolyn Roper in Manchester, UK on May 16, 2016 as part of the #CountThemIn campaign launched on Monday by the Royal British Legion. (Photo by Jon Super/Royal British Legion/PA Wire)

People in costume take photos during a Halloween event on October 31, 2015 in Lan Kwai Fong, Central District, Hong Kong. Halloween, a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Jerome Favre/Getty Images)

Juno, a Beluga whale, greets a young viewer at the Mystic aquarium in Connecticut, USA on December 5, 2015. (Photo by Tim Clayton/Corbis)

A 40-foot sculpture of the swimmer Rebecca Adlington was unveiled at the Serpentine in London’s Hyde Park on July 25, 2016 to launch a campaign by Kelloggs to encourage the public to support Team GB at the Rio Olympics. (Photo by David Parry/PA Wire/Barcroft Images)

“Show Time”. It's a normal behavior of mantis. They're doing defence. When they're afraid of; raising their arms and spreading their wings. They looks like smiling dancer. Photo location: Nicosia, Cyprus. (Photo and caption by Hasan Baglar/National Geographic Photo Contest)