Two three-month-old female white Bengal tiger cubs play with a zoo keeper in their enclosure at the Buenos Aires' Zoo, in Argentina, on April 17, 2014. Captive white Bengal tiger Cloe, gave birth to three cubs – two females and one male – on January 14, 2014. (Photo by Juan Mabromata/AFP Photo)

A woman dressed for la “La Diablada” festival, walks down a road in Pillaro, Ecuador, Friday, January 6, 2017. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

“Festive preparation”. Baghnapara, Bardhaman, West Bengal, India. Two girls prepare for the Gajan festival. They will perform a play based on Indian mythology. (Photo by Krishnasis Ghosh)

A construction worker sweeps up as the final touches are completed on “Comedy Carpet” by British artist Gordon Young, the latest art installation on Blackpool's promenade on October 7, 2011 in Blackpool, England. (Photo by Christopher Furlong/Getty Images)

A man dressed as Ironman takes a seat in the cafeteria on the second day of the London Super Comic Convention at the ExCel centre in east London, on March 15, 2015. (Photo by Justin Tallis/AFP Photo)

Stumpy the lemur has just turned 27 and is believed to be the oldest ring-tailed lemur in the world. He's still loving life, according to Zoo keepers. (Photo by Hemedia/Swns Group)

Metropolitan Transit Authority (MTA) Police Officer Keith Flood trains with his K-9 partner Doc, a German Shepherd, inside the “warehouse room” at the new MTA Police Department Canine Training Center in Stormville, New York, U.S., June 6, 2016. (Photo by Mike Segar/Reuters)

This huge male orangutan is having a right old laugh as he squints his eyes and shows his huge teeth. The orangutan, called Bimbo, was relaxing on a platform around 5m high in his enclosure when he broke out into a laugh. But his happy smile soon disappeared when another orangutan came over to see what was going on. Bimbo – the only male in the group of five apes at Leipzig Zoo, in Germany - appears to be laughing in much the same way as a human would. (Photo by Martina Radtke/Solent News)