A passenger without pants waits for the subway train during “The No Pants Subway Ride” in Mexico City January 11, 2015. The event, the fifth organized in Mexico, is an annual flash mob and occurs in different cities around the world, according to its organisers. (Photo by Edgard Garrido/Reuters)

A model applies lipstick backstage during the “We Love Flamenco” fashion show in the Andalusian capital of Seville January 14, 2015. The show will run until January 18. (Photo by Marcelo del Pozo/Reuters)

A swimmer competes during the UK Cold Water Swimming Championships at Tooting Bec Lido in south London January 24, 2015. (Photo by Luke MacGregor/Reuters)

A person dressed as “bigfoot” makes their way through the strong wind and snow in the Back Bay neighborhood during a blizzard on January 27, 2015 in Boston, Massachusetts. (Photo by Kayana Szymczak/Getty Images)

Migrating starlings fly in formation near the southern Israeli town of Rahat February 2, 2015. The phenomenon, known as murmuration, is most common during the winter months. (Photo by Nir Elias/Reuters)

A model displays a creation for designer Andres Sarda's Fall/Winter 2015 collection, during the Mercedes-Benz Fashion Week in Madrid, February 7, 2015. (Photo by Javier Barbancho/Reuters)

A young prince, dressed ready for the coronation of new Emir of Kano Muhamadu Sanusi II, is pictured in Kano, Kano State, February 7, 2015. (Photo by Afolabi Sotunde/Reuters)

Arctic wolves in their new enclosure in the wildlife park in Hanau, Germany, 10 February 2015. The pack is one of the park's main attractions, which specializes in local and European breeds. (Photo by Boris Roessler/EPA)