Azalea, whose Korean name is “Dalle”, a 19-year-old female chimpanzee, lights a cigarette at the Central Zoo in Pyongyang, North Korea on Wednesday, October 19, 2016. According to officials at the newly renovated zoo, which has become a favorite leisure spot in the North Korean capital since it was re-opened in July, the chimpanzee smokes about a pack a day. They insist, however, that she doesn’t inhale. (Photo by Wong Maye-E/AP Photo)

Khan, a five-year-old male White Bengal tiger, looks on inside an open-air cage at the Royev Ruchey zoo in Krasnoyarsk, Russia, October 21, 2016. (Photo by Ilya Naymushin/Reuters)

A West African Slender-snouted Crocodile is pictured in its enclosure at the zoo of Abidjan, Ivory Coast September 9, 2016. (Photo by Luc Gnago/Reuters)

A “jungle nymph” is measured during the annual weight-in ZSL London Zoo on August 21, 2014 in London, England. The height and mass of every animal in the zoo, of which there are over 16,000, is recorded and submitted to the Zoological Information Management System. This is combined with animal measurement data collected from over 800 zoos and aquariums in almost 80 countries, from which zoologists can compare information on thousands of endangered species. (Photo by Oli Scarff/Getty Images)

A zoo worker feeds milk to tiger cubs born on the first day of the Lunar New Year and Year of the Rooster at Sriracha Tiger Zoo in Chonburi province, Thailand, January 30, 2017. (Photo by Athit Perawongmetha/Reuters)

“My name is In Cherl Kim. I'm a PR manager of Samsung Everland. Everland is a largest theme park in South Korea. Everland has a variety of attractions and flower garden and entertainment. Among other things, Everland zoo is very unique place!” – In Cherl Kim. Photo: Ring tailed lemur. (Photo by In Cherl Kim)

Baby clouded leopards, born early in March 2015, are presented by zoo keepers at the Olmense Zoo in Olmen, Belgium, April 16, 2015. The clouded leopard is an endangered species with only some 10,000 specimen remaining on earth, said Robby Van der Velden, a biologist at the Olmense Zoo. (Photo by Yves Herman/Reuters)

A zookeeper feeds a hippopotamus with a watermelon in its enclosure in Belgrade's zoo, Serbia, July 20, 2015. Temperatures in Serbia have risen up to 40 degrees Celsius (104 degrees Fahrenheit), according to official meteorological data. (Photo by Marko Djurica/Reuters)