In this photo taken on Monday, January 5, 2015, a mallard duck attempts to walk on a frozen pond in Yukon, Okla. (Photo by Steve Gooch/AP Photo/The Oklahoman)
Shoppers walk past crocodiles for sale at a market in Bata on February 3, 2015. Markets in Equatorial Guinea sell a variety of animals including pangolins, monkeys and crocodiles as food. (Photo by Carl De Souza/AFP Photo)
A woman dressed up as a zombie takes part in a zombie walk in the Gaslamp Quarter during the Comic Con International convention in San Diego, California July 13, 2012. (Photo by Mario Anzuoni/Reuters)
Contestants walk on stage during the “mini-miss” beauty contest in Bobigny, Paris suburb, September 22, 2012. The competition is open for girls aged 7 to 12. (Photo by Benoit Tessier/Reuters)
A donkey carrying sacks of coal walks through the narrow tunnels of a coal mine, in Choa Saidan Shah in Punjab province April 29, 2014. Coal miners in Chao Saidan Shah use donkeys to transport coal from the depths of the mines to the surface. (Photo by Sara Farid/Reuters)
A model walks off stage in the backstage area during Frankie's Bikinis show at Mercedes Benz Swim Fashion Week in Miami, July 18, 2014. (Photo by Carlo Allegri/Reuters)
A model walks the runway in the Maria Escote fashion show during the Mercedes-Benz Fashion Week Madrid Autumn/Winter 2012 at Ifema on February 4, 2012 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)
A model walks the runway at the Popluxe Fall 2012 fashion show during Mercedes-Benz Fashion Week at The Studio at Lincoln Center on February 10, 2012 in New York City. (Photo by Frazer Harrison/Getty Images)