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 Haitian woman lies in a trance during a voodoo ceremony in Souvenance, a suburb of Gonaives, 171 km north of Port- au- Prince, on April 16, 2017. Haitian voodoo followers arrived in Souvenance to take part in the voodoo ceremonies held during Easter weekend. (Photo by Hector Retamal/AFP Photo)

Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

A lemur licks a block of ice containing fruit at Rome's Bioparco zoo, Wednesday, July 5, 2017. Zookeepers at the Bioparco often give animals ice blocks with either fruit or meat on hot summer days. (Photo by Gregorio Borgia/AP Photo)

Japanese chorus girls appear to be drilling in military tactics atop their theater building as they perform salutes, June 30, 1937. The officer is from the Japanese regular army and says the girls display more rhythm in their drills than do the regular troops. (Photo by AP Photo)

Museum employee Victoria views a giant grouper fish specimen at the Natural History Museum in west London March 25, 2015. It forms part of a new exhibition, “Coral Reefs: Secret Cities of the Sea”, featuring a panoramic virtual dive and over 250 specimens from the Museum's coral, fish and marine invertebrate collection, which opens on March 27. (Photo by Toby Melville/Reuters)

A young man weaves palm fronds into the shape of a cross before the start of a Mass to observe Palm Sunday, at the Metropolitan Cathedral, in Managua, Nicaragua, Sunday, March 29, 2015. For Christians, Palm Sunday marks the start of Holy Week ahead of Easter, commemorating Jesus Christ's entrance into Jerusalem, when his followers laid palm branches in his path. (Photo by Esteban Felix/AP Photo)

Students dance in the hallway during a break at Moscow State Academy of Choreography in Moscow, Russia 03 March 2016. Moscow State Academy of Choreography is the oldest institution in Moscow which teaches Ballet arts not only Russian citizens, but also representatives from more than 20 countries. (Photo by Yuri Kochetkov/EPA)