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)

A three-week-old chihuahua puppy named Tom Thumb poses in a tea cup on April 7, 2009 in Renton, Scotland. The pup, which measures eight inches long, is thought to be one of the smallest dogs born in the UK and is just two inches short of a world record. (Photo by Jeff J Mitchell/Getty Images)

Odin, a five year-old White Bengal Tiger dives for a piece of meat thrown to him by a trainer during a big cat show at Six Flags Discovery Kingdom June 1, 2007 in Vallejo, California. Unlike most cats that are afraid of water, Odin loves diving in the pool to retrieve bits of meat fed to him by his trainers. (Photo by Justin Sullivan/Getty Images)

An orphaned 11 month old cougar cub plays at Six Flags Discovery Kingdom on April 26, 2007 in Vallejo, California. Three cougar cubs were given to the park from the Idaho Fish & Game in March after they were found motherless in the wild and it was determined that they would not survive in the wild. (Photo by David Paul Morris/Getty Images)

Chinese Panda Yang Guang arrives at Edinburgh Airport on December 4, 2011 in Edinburgh, Scotland. Tian Tian and Yang Guang, a pair of eight-year-old giant pandas arrived on a specially chartered flight and will be the first to live in the UK for 17 years. Edinburgh Zoo are hopeful that the pandas will give birth to cubs during their 10 year stay in Scotland. (Photo by Jeff J Mitchell/Getty Images)

Members of the 3rd U.S. Infantry Regiment place American flags at the graves of U.S. soldiers buried at Arlington National Cemetery in preparation for Memorial Day May 26, 2011 in Arlington, Virginia. “Flags-In” has become an annual event since the 3rd U.S. Infantry Regiment (The Old Guard) was appointed an Army official ceremonial unit in 1948. Every available soldier in the 3rd U.S. Infantry Regiment participates in these annual ceremonies. (Photo by Win McNamee/Getty Images)

Hwang Bo-young (L), a North Korean defector who was a member of the North Korean National female ice hockey team, prepares for practice with South Korean teammates on March 13, 2006 in Seoul, South Korea. Young, 27-years-old, became a captain of the South Korean National Female Ice Hockey Team. (Photo by Chung Sung-Jun/Getty Images)

Banger racers take part in one of the final races of the banger racing season at the Mendip Raceway on October 9, 2011 in Cheddar, England. Banger racing is a popular contact motorsport, especially in the UK and Ireland – in which drivers of old and scrap vehicles race against one another around a dirt or tarmac race track, while deliberately attempting to destroy opposing vehicles. (Photo by Matt Cardy/Getty Images)