Emily Hasler, an English Heritage employee at Charles Darwin's home, Down House, cleans a rabbit bone in his old study on April 2, 2011 in Downe, England. Staff at the house are cleaning and preparing the property ahead of their peak visitor season. The house contains the study where Darwin wrote “On the Origin of Species”, as well as family rooms and an extensive garden that inspired the renowned scientist. (Photo by Oli Scarff/Getty Images)

Metropolitan Police officers prepare to carry out a raid on a property on the Churchill Gardens estate in Pimlico during Operation Woodstock on August 11, 2011 in London, England. Over 1,000 people have been arrested since the rioting began on Saturday and Police have started to raid properties across the capital as they round up people suspected of involvement in the rioting and recover stolen property. (Photo by Anthony Devlin - WPA Pool/Getty Images)

One of the nine baby flamingos born at Bristol Zoo stands with the adults as they feed together on August 19, 2011 in Bristol, England. Nine flamingo chicks have hatched at Bristol Zoo Gardens in the last three months – the biggest number the Zoo has ever had. The chicks, which are Greater Flamingoes from Africa and southern Europe and range in age from four weeks to three months old, take the Zoo's total flock to 38 birds. (Photo by Matt Cardy/Getty Images)

With six-inch fangs and weighing in at 600lb, Saber and Janda are no ­ordinary house cats. Yet these huge Bengal tigers live in Janice Haley’s suburban garden and are treated like ordinary pets. They are fed by hand, get strokes and cuddles, and white male Saber goes to sleep sucking on her finger. Janice’s life changed 20 years ago when she spotted an advert for a tiger training course in her local paper – and two years later arrived home with her first cub. Then in 2002 she bought Janda, who is now 12. Photo: The pair are best of friends. (Photo by Ruaridh Connellan/Barcroft Media)

Jorge, an immigrant from Mexico, dressed as the Sesame Street character Elmo rests in Times Square, New York July 29, 2014. Elmo and Cookie Monster have long delighted young viewers on TV's “Sesame Street”, but the recent antics of New York street performers dressed as the beloved characters have drawn the ire of city officials and now the show's producers. Sesame Workshop, which owns the rights to Big Bird, Ernie and the assorted puppet monsters on the 45-year-old program, said on July 29, 2014 it was drafting plans to stop performers who dress up as the characters from appearing in Times Square, where they pose for photos with tourists and then demand tips. (Photo by Eduardo Munoz/Reuters)

Miss Universe contestant Carolina Duran of Costa Rica, center, reacts to a TV network's drone as others prepare to pose from the deck of the yacht Happy Life prior to cruising to a beach resort in Batangas province Thursday, January 19, 2017 at the Philippine Navy headquarters in Manila, Philippines. Eighty-six candidates from around the world are vying for the title to succeed Pia Wurtzbach from the Philippines. The competition takes place on Jan. 30. They are, from left, Cherell Williamson of Bahamas, Rebecca Rath of Belize, Hildur Maria of Iceland, and Chanelle de Lau of Curacao. (Photo by Bullit Marquez/AP Photo)