Tamberly Conway, bottom left, takes part in a large snowball fight in Dupont Circle on Sunday January 24, 2016 in Washington, DC. The Washington, DC area was blanketed by a large snow event. (Photo by Matt McClain/The Washington Post)

A rebel fighter supporter shoots an AK-47 rifle as she reacts to the news of the withdrawal of Libyan leader Muammar Gaddafi's forces from Benghazi March 19, 2011. The conflict was sparked by clashes in Benghazi and escalated into a rebellion that spread across the country. Gaddafi was captured and killed on October 20, 2011. Libya is currently caught up in a conflict between two rival factions who once battled together against the late Libyan leader. (Photo by Goran Tomasevic/Reuters)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Ave, 4 years-old, of the United States, paints on her father's hand during the International Tattoo Convention Bucharest 2016 in Bucharest, Romania, Sunday, October 16, 2016. Prominent tattoo artists from across the world displayed their skills in the Romanian capital over the weekend. (Photo by Vadim Ghirda/AP Photo)

People wearing costumes pose for a photograph as they participate in the annual “Zombie Walk” in Bordeaux, France on October 22, 2016. Several hundred people wearing costumes and makeup took part in the walk which was authorized despite the state of emergency. (Photo by Georges Gobet/AFP Photo)

Mature woman lying on bed, rear view. (Photo by Andersen Ross/Getty Images)

In this January 7, 2017 photo, Judeley Hans Debel squats down to remove a boot from Tic Tac, holding out his prosthetic leg after his therapeutic riding lesson at the Chateaublond Equestrian Center in Petion-Ville, Haiti. Anne-Rose Schoen, who founded the equestrian center, said perhaps the most important thing about therapeutic riding is it makes youngsters happy in a country where disabled people face enormous challenges. (Photo by Dieu Nalio Chery/AP Photo)

A gibbon drinks from a soft drink bottle, given by a tourist, at a zoo in Kunming, Yunnan province, June 18, 2015. (Photo by Wong Campion/Reuters)