Ranger trainees and trainee dogs simulate an ambush against rhino poachers at the Paramount Group Anti-Poaching training and K9 (canine) academy on November 26, 2014 in Magaliesberg, South Africa. One of the largest of its kind in Africa, the Academy will address the ever increasing need for training of Conservation Officers in anti poaching activities, wildlife contraband detection, specialist K9 solutions and Ranger K9 handler training – all of which have proven success rates in combatting and apprehending poachers and their activities. (Photo by Gianluigi Guercia/AFP Photo)

A man lies on the floor during a ritual at the Sorte Mountain on the outskirts of Chivacoa, in the state of Yaracuy, Venezuela October 10, 2015. One long night every year in a mountainous rainforest in Venezuela, hundreds gather to dance on red-hot embers, enter trance-like states, and worship an ancient goddess known as Maria Lionza. Those who travel to the mountain known as Sorte in central Venezuela are practitioners of a cult that is built on local indigenous traditions. (Photo by Marco Bello/Reuters)

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)

Yana Shcherban of Russia looks at the ball after failing to receive it during their FIVB Women's Volleyball World Grand Prix 2014 final round against Japan in Tokyo August 20, 2014. (Photo by Yuya Shino/Reuters)

A lunar eclipse appears behind a gargoyle atop the old red Dallas County Courthouse early Wednesday morning, October 8, 2014. The moon appears orange or red, the result of sunlight scattering off Earth's atmosphere. This is known as the blood moon. (Photo by Tom Fox/AP Photo/The Dallas Morning News)

A truck is seen in a hole after part of the structure of a bridge collapsed into a river in Changchun, Jilin province May 29, 2011. Two truck passengers were injured, while the cause of the accident is still under investigation, local media reported. (Photo by Reuters/China Daily)

A model falls over on the runway in a design by Victoria Bliss during the Project NextGen show at Mercedes-Benz Fashion Week Resort 18 Collections at Carriageworks on May 16, 2017 in Sydney, Australia. (Photo by Stefan Gosatti/Getty Images)

Young U.S. visitors pose for a photograph next to a vintage car in Havana March 16, 2016. (Photo by Ueslei Marcelino/Reuters)