Two chimpanzees share a piece of watermelon at Taronga Zoo on December 23, 2010 in Sydney, Australia. (Photo by Rick Stevens/Taronga Zoo via Getty Images)

Five year old Michael Esteban and his mother Kari Esteban, crawl through a 40-foot long, 4-foot high replica of a human colon on July 11, 2003 in Seattle. The colon is used to educate people on colorectal cancer. (Photo by Ron Wurzer/Getty Images)

A lighting bolt flashes in the sky as U.S. Army M1A1 Abram tanks roll through the desert December 9, 2002 near the Iraqi border in Kuwait. (Photo by Joe Raedle/Getty Images)

A girl has her helmet adjusted on the top of a tank during the Children's Day celebration at a military facility in Bangkok, Thailand January 9, 2016. Army barracks opened their doors to children to interact with their weapons and vehicles as part of the celebration. (Photo by Jorge Silva/Reuters)

Brazilian top model Gisele Bundchen poses before a fashion show by German designer Karl Lagerfeld as part of his latest inter-seasonal Cruise collection for fashion house Chanel at the Paseo del Prado street in Havana, Cuba, May 3, 2016. (Photo by Alexandre Meneghini/Reuters)

A Russian daredevil has captured a vertigo-inducing selfie – while standing on top of a Dubai skyscraper. Nineteen-year-old Alexander Remnev scaled the Princess Tower – the worlds tallest residential building at 1,350ft – before getting his camera out to take these stomach-churning pictures. Photo: He leans on the very top of the tower as he takes this vertigo-inducing picture. (Photo by Alexander Remnev/Caters News)

This picture taken on July 25, 2014 shows people cooling off in a waterpark in Suining, southwest China's Sichuan province. Meteorological departments issued an orange alert for high temperature as a heat wave embraces Sichuan province, with temperature of most area topped 37, local media reported. (Photo by AFP Photo)

An alpaca is seen near the Inca citadel of Machu Picchu in Cusco December 2, 2014. Machu Picchu, a UNESCO World Heritage Site, is Peru's top tourist attraction, with the government limiting tourists to 2,500 per day due to safety reasons and concerns over the preservation of the ruins. (Photo by Enrique Castro-Mendivil/Reuters)