Girls play with their new dolls during the distribution of free toys for low-income families and a picture on the lap of one of the Three Wise Men at Almudena Cathedral in Madrid, Spain, December 22, 2015. Traditionally, children in Spain receive their presents delivered by the Three Wise Men on the morning of January 6 during the Christian holiday of the Epiphany. (Photo by Susana Vera/Reuters)

14 week-old twin polar bear cubs play during their first presentation to the media in Hellabrunn zoo on March 19, 2014 in Munich, Germany. The male and female twins were born on December 9, 2013 in the zoo. (Photo by Alexandra Beier/Getty Images)

Swedish brown bears “Fred” and “Frode” play in the snow on January 30, 2014 at the Natur- und Umweltpark (NUP) animal park in Guestrow, northeastern Germany. Despite of icy temperatures, the bear brothers took a break from their winter rest. (Photo by Bernd Wuestneck/AFP Photo/DPA)

A man playing the part of a zombi pretends to rise from the dead from inside a coffin at a Carnival parade in Jacmel, Haiti, Sunday, February 23, 2014. The pre-Lent festival began in the streets of this town known for its arts to kick off Haiti’s Carnival festivities. (Photo by Dieu Nalio Chery/AP Photo)

An adult chimp plays with a young chimp at Chimp Haven in Keithville, La., Monday, February 18, 2013. One hundred and eleven chimpanzees will be coming from a south Louisiana laboratory to Chimp Haven, the national sanctuary for chimpanzees retired from federal research. (AP Photo/Gerald Herbert)

An actor carries a cross as he plays the role of Jesus Christ in a re-enactment of the Via Crucis (Way of the Cross) during a Holy Week procession, in preparation for Good Friday celebrations, in Luque, Paraguay, on March 27, 2013. Holy Week is celebrated in many Christian traditions during the week before Easter. (Photo by Jorge Adorno/Reuters)

A security personnel plays with a girl in the compound of a health and rest centre which serves as a temporary accommodation for refugees from eastern regions of the country in the town of Korostyshiv, Zhytomyr region, Ukraine, July 30, 2015. More than 400 people who left eastern Ukraine due to a military conflict have arrived at the sanatorium in Korostyshiv since the summer of 2014, according to representatives. (Photo by Valentyn Ogirenko/Reuters)

A girl plays with colourful papers at the 23rd Sziget (Island) Festival on Shipyard Island in Budapest, Hungary, 13 August 2015. The festival is one of the biggest cultural events of Europe, offering art exhibitions, theatrical and circus performances and music concerts. Almost 200 performers from 47 countries will entertain the hundreds of thousands of visitors from 11 to 18 August. (Photo by Balazs Mohai/EPA)