A zoo staff feeds crocodiles as visitors look on at the Malabon Zoo in Malabon City, north of Manila, Philippines 21 December 2017. Wearing Santa Claus hats for the upcoming Christmas season, owner Manny Tangco (R, holding megaphone) and some select animals gave visitors a tour of the 28-year-old zoo. (Photo by Rolex Dela Pena/EPA/EFE)

Khansa, an eight month old critically endangered Bornean orangutan shows off it's two front-teeth, at the Singapore Zoo on Thursday, January 11, 2018 in Singapore. The Singapore Zoo is active with its breeding programs as part of its wildlife preservation efforts. This is the Zoo's 46th successful orangutan birth. (Photo by Wong Maye-E/AP Photo)

A keeper feeds a four-week-old jaguar while presenting it to the media, at a zoo in Ciudad Juarez, Mexico, October 14, 2015. (Photo by Jose Luis Gonzalez/Reuters)

A heat-stressed koala waits as a resident pours water on its back on December 19, 2015 in Adelaide, Australia. Adelaide is experiencing an extreme heatwave, with temperatures reaching over 40 degrees for five consecutive days. (Photo by Morne de Klerk/Getty Images)

A butterfly flies into the jaws of a crocodile inhabiting the Tarcoles River, the most polluted basin in Central America and one of the most polluted in Latin America, in the place of Tarcoles, province of Puntarenas, Costa Rica, 05 June 2018. Costa Rica, a country recognized worldwide for its environmental policies, seeks to be a leader in the replacement of single-use plastic with renewable and compostable alternatives, despite its lag in terms of recycling and integrated waste management. (Photo by Jeffrey Arguedas/EPA/EFE)

Two horses appear to burst into laughter before a sweet embrace. The horses both turn their head to look at the camera and flash their teeth, treating the lucky photographer to a rare shot. Moments later the pair show their affectionate side by coming together and “hugging”. Photographer Nir Amos, 34, said he was “amazed” to capture the horses “laughing” in a field near Skógar, in the south east of Iceland on July 31, 2018. (Photo by Nir Amos/Solent News & Photo Agency)

Two brown bears bathe in their enclosure at the Wildpark Poing in Poing, Germany, Wednesday, August 8, 2018. (Photo by Lino Mirgeler/Deutsche Presse-Agentur via AP Photo)

An alligator named Muja is seen in its enclosure in Belgrade's Zoo, Serbia, August 14, 2018. Muja is officially the oldest American alligator in the world living in captivity. He was brought to Belgrade from Germany in 1937, a year after the opening of the Zoo. Muja survived three bombings of Belgrade, the Second World War and all hardships the Zoo went through. (Photo by Marko Djurica/Reuters)