A 20-year-old Japanese macaque monkey named Monday scratches her eyes while suffering an allergy to pollen from the cedar tree at Awajishima Monkey Centre on March 17, 2013 in Sumoto, Japan. Many monkeys are suffering the effects of hay fever at this time of the year, with the typical symptoms being the same as with humans. According to Awajishima Monkey center this year hay fever is higher than last year, the pollen season is from February to April. (Photo by Buddhika Weerasinghe)

A sticker is seen at the Rocky Mountain Guns and Ammo store in Parker, Colorado July 24, 2012. The killing of 12 people at a midnight screening of the new Batman movie in the Denver suburb of Aurora may spark a fresh round of soul-searching on America's relationship with guns but few predict any real change in the law. (Photo by Shannon Stapleton/Reuters)

Revellers celebrate the death of Britain's former prime minister Margaret Thatcher in Brixton, south London April 8, 2013. Margaret Thatcher, the “Iron Lady” who transformed Britain and inspired conservatives around the world by radically rolling back the state during her 11 years in power, died on Monday following a stroke. She was 87. (Photo by Olivia Harris/Reuters)

A man takes a photo of a radio antenna that's part of the Atacama Large Milimeter Array Observatory on March 12, 2013 at Llano de Chajnantor, about 43 miles (70 kilometers) from San Pedro de Atacama, Chile. The $1.5 billion ALMA facility, which had its official inauguration on March 13, is considered the world's most expensive ground-based observatory. (Photo by Felipe Trueba/EPA)

Brazilian graffiti artist Eduardo Kobra (C) puts the final touches to his piece of art in tribute to Brazilian architect Oscar Niemeyer, next to his assistants, at the financial center on Sao Paulo's Avenida Paulista January 22, 2013. Kobra created the 56-metre (61-yard) tall graffiti artwork as a tribute to Niemeyer, one of the 20th century's most influential modernist architects. Niemeyer died in December 2012, aged 104. (Photo by Andre Penner/AP Photo)

Faithful carry a boat out to sea, filled with offerings to Yemanja, the African sea goddess, during a ceremony honoring the deity in Montevideo, Uruguay, Saturday, February 2, 2013. Thousands of worshippers come to the beach in Montevideo on her feast day, February 2, bearing candles, flowers, perfumes and fruit to show their gratitude for her blessings bestowed upon them. The belief in the goddess sprouts from Umbanda, a blend of religions that include African, Catholicism and Spiritism. (Photo by Matilde Campodonico/AP Photo)

A boy poses with a butterfly on his face during a photocall to promote the “Sensational Butterflies” exhibition at the Natural History Museum in central London, on March 25, 2013. With around 400 live tropical butterflies and moths living in the temporary facility, visitors will get the chance to see them flying freely as well as looking for emerging butterflies at the hatchery window. Running from March 29 to September 15, 2013, the exhibition is housed in a structure in the museum grounds. (Photo by Leon Neal/AFP Photo)