Sugar gliders, Candy and Popcorn, enjoy their favourite food, Nectar, at Wild Life Sydney Zoo on February 14, 2017 in Sydney, Australia. The treat made up of honey, high protein baby cereal and egg yolks is the human equivalent to chocolate to the Sugar Gliders. St. Valentine's Day or the Feast of Saint Valentine began as a celebration of the early Christian Saint Valentinus. From the 18th Century onwards it has steadily transformed into a celebration of romantic love and sentiment in many countries around the world. (Photo by James D. Morgan/Getty Images)

A confiscated female orangutan smuggled from Indonesia looks out from a cage before being sent back home to Indonesia, at Khao Pratupchang Wildlife Breeding Center in Ratchaburi province, Thailand, 11 November 2015. According to media reports, Thailand will return fourteen smuggled orangutans to Indonesia on 12 November, after Thai authorities found them in 2010 by a roadside in Phuket province, apparently on their way to a private zoo. (Photo by Narong Sangnak/EPA)

Indian authorities hold a tiger skin as they set fire to a stockpile of illegal wildlife parts at the Delhi Zoo in New Delhi, India, Sunday, November 2, 2014. A stockpile of tiger skins, elephant tusks, rhino horns and other illegal animal parts were burned Sunday in an effort to discourage wildlife smuggling in South Asia. (Photo by Tsering Topgyal/AP Photo)

Young African lion Asali (R) jumps for a bungee-ball toy as her father Jambo or “Bruiser” looks on at the opening of a savannah-themed makeover of the lion enclosure at Taronga Zoo August 29, 2006 in Sydney, Australia. The renovation includes sandstone rock features, a wading pool, and red ochre crushed granite substrate in a move to make the enclosure more closely resemble the natural habitat of the African savannah. (Photo by Ian Waldie/Getty Images)

Adult gentoo penguins keep an eye on their newly born chick at Edinburgh Zoo on June 10, 2011 in Edinburgh, Scotland. The gentoo chicks which started hatching in early May are looked after by both parents who regurgitate part digested food. When the chicks are hungry they peck the beaks of their parents to signal feeding time. (Photo by Jeff J Mitchell/Getty Images)

These zoo animals take on an altogether more sinister look after posing for a set of moody black and white portraits. Alex Teuscher has brought out the dark side in a range of exotic creatures with his artistic project which took two years to complete. Photo: White tiger. (Photo by Alex Teuscher/BNPS)

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)

These portraits reveal the incredibly humanlike expressions of a variety of apes.Through piercing eyes and finite facial details, the intimate photographs show the animals looking angry, sad, delighted and pensive. They are the works of Manuela Kulpa – an IT consultant and keen photographer from near Cologne, Germany – who shot the apes predominantly at zoos across Austria, Belgium, the Czech Republic, Germany and the Netherlands. Here: Bonobo, Azibo. (Photo by Manuela Kulpa/Caters News)