A baby hippo swims under the water in its enclosure at Prague Zoo, Czech Republic, February 24, 2016. The baby was born on January 28, and is yet to be named. (Photo by David W. Cerny/Reuters)

Edinburgh Zoo is proud to introduce this baby three-banded armadillo Rica who was born to mum Rio and dad Rodar in Edinburgh, Scotland, UK on Sunday 24 August 2014. A tiny 81g at birth and around the same size as a golf ball, Rica is a female three banded armadillo who has grown rapidly in her first month, already quadrupling in weight. (Photo by SWNS/ABACAPress)

A child looks at a polar bear swimming under a water in its enclosure on a hot summer day at Prague Zoo, Czech Republic, July 30, 2015. (Photo by David W. Cerny/Reuters)

Light sculptures glow in the dark at the zoo in Cologne, Germany, 04 December 2019. The artworks are on display at the zoo as part of the China Light Festival that runs until 09 January 2020 and features more than 70 light installations on the zoo grounds. (Photo by Sascha Steinbach/EPA/EFE)

A Western Lowland Gorilla baby named “Mjukuu”, that was born in October last year, rides on the back of its Mother “Mbeli” in their enclosure at Taronga Zoo in Sydney, Australia, May 19, 2015. The baby gorilla was born six days ago, and is the second sired by the zoo's new Silverback, Kibali, who arrived from France in 2012. (Photo by David Gray/Reuters)

Karishma, a 13 year old female Asian elephant, paints at an easel in her enclosure at ZSL Whipsnade Zoo on September 20, 2011 in Dunstable, England. A selection of Karishma's artwork will go on display at the Zoo this weekend to celebrate Elephant Appreciation Day. (Photo by Oli Scarff/Getty Images)

In this image provided by the Pairi Daiza park, giant panda Hao Hao holds her newborn baby in her mouth at the park in Brugelette, Belgium, on Thursday, June 2, 2016. With the help of the Chinese government Hao Hao and her mate Xing Hui arrived in Belgium two years ago and Pairi Daiza adapted its park to build a bamboo forest for them. (Photo by Benoit Bouchez/Pairi Daiza via AP Photo)

A three month-old baby gorilla named Hasani sits in the grass March 11, 2009 at the San Francisco Zoo in San Francisco, California. The newborn gorilla was given the name Hasani. Hasani's father, a twenty seven year-old gorilla named Oscar Jonsey, picked between five color coded cantaloupes representing the five name finalists to come up with the newborn's name that was submitted by Amanda VerPloeg of Oskaloosa, Iowa. (Photo by Justin Sullivan/Getty Images)