An anti-Gaddafi fighter tests an anti-aircraft gun southwest of Sirte, Libya one of Muammar Gaddafi's last remaining strongholds, September 16, 2011. A timeline of images dating from 2010 from Sirte, Libya, the home town of deposed Libyan leader Muammar Gaddafi. Libyan forces battling Islamic State in the city of Sirte say they have defeated the militant group after months of street to street fighting backed by U.S. air strikes. Islamic State took control of the city more than a year ago and set up its main base outside Syria and Iraq. (Photo by Goran Tomasevic/Reuters)

Galapagos – Rocking the Cradle: Four major ocean currents converge along the Galapagos archipelago, creating the conditions for an extraordinary diversity of animal life, April 25, 2016. The islands are home to at least 7,000 flora and fauna species, of which 97 percent of the reptiles, 80 percent of the land birds, 50 percent of the insects and 30 percent of the plants are endemic. (Photo by Thomas P. Peschak for National Geographic/World Press Photo)

British tourists snap a cheeky selfie with a monkey at the Ubud Monkey Forest in Bali, Indonesia, August 4, 2015. George Benton, 22, from Paignton, Devon was visiting the Sacred Monkey Forest Sanctuary in Ubud, Bali whilst traveling with his girlfriend Chloe when the couple snapped a surprise shot with Balinese long-tailed monkey using a “selfie stick”. “We couldn't believe our luck when we looked back at the photos, he looked straight into the camera!” said George, who went on to reward the cheeky chap with a banana for giving the couple such a memorable photo. (Photo by George Benton/Splash News)

People cool off in a fountain outside the Southbank Centre on June 30, 2015 in London, England. The UK is currently experiencing a heatwave, with temperatures of 35 degree celsius forecast tomorrow in some parts of the country. The extreme heat has already seen train cancellations and a health warning has been issued. (Photo by Rob Stothard/Getty Images)

Madison Chock and Evan Bates of the U.S. compete during the ice dance short dance program at the ISU World Team Trophy in Figure Skating in Tokyo April 16, 2015. (Photo by Yuya Shino/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)

A woman poses as she has her picture taken amid 1600 panda bear sculptures in Berlin August 5, 2013. Marking the 50th anniversary of its existence, on Monday the German branch of the World Wide Fund for Nature (WWF) environmental conservation organisation placed 1600 panda bear sculptures on front of Berlin's main train station to draw attention to the plight of the endangered species that serves as the NGO's mascot. There are currently 1600 panda bears alive in the wild, the organisation said in a press release. (Photo by Thomas Peter/Reuters)

A sticker is seen at the Rocky Mountain Guns and Ammo store in Parker, Colorado July 24, 2012. The killing of 12 people at a midnight screening of the new Batman movie in the Denver suburb of Aurora may spark a fresh round of soul-searching on America's relationship with guns but few predict any real change in the law. (Photo by Shannon Stapleton/Reuters)