One of three young oriental small-clawed otters eats a meatball on June 18, 2015 in a zoo in Dresden, eastern Germany. The oriental small-clawed otter female Fussi gave birth to 3 healthy pups. Its pups now leave their burrow to explore the environment. (Photo by Arno Burgi/AFP Photo/DPA)

“Left behind” children Luo Hongni, 11 (L) and brother Luo Gan,10, carry flowers to be used as feed while doing chores in the fields on December 18, 2016 in Anshun, China. Like millions of Chinese children, the four Luo siblings are being raised by their grandparents in rural China as their parents left to find work in urban areas. (Photo by Kevin Frayer/Getty Images)

An Orchid Mantis (Hymenopus coronatus) is perched on the head of a frog hanging from a tree branch on March 15, 2017 in Padang, Indonesia. (Photo by Riau Images/Barcroft Images)

An Indian nomadic Gujjar girl hangs on to a horse cart after collecting bricks from debris on the outskirts of Jammu, India, Tuesday, March 7, 2017. The Gujjar tribal communities are considered by some to be economically and socially backward and the lack of care by the state government has led to resentment amongst the community. The tribe moves to the plains from the hills to escape the cold winters. (Photo by Channi Anand/AP Photo)

Nutrias venture near the camera at the river Nidda in Frankfurt am Main, Germany, 15 June 2017. The rabbit sized animals are often confused with biebers by amateurs. (Photo by Boris Roessler/DPA)

Chinese soldiers leave after Chinese President Xi Jinping inspected troops of People's Liberation Army (PLA) Hong Kong Garrison at the Shek Kong Barracks in Hong Kong, Friday, June 30, 2017. Xi landed in Hong Kong Thursday to mark the 20th anniversary of Beijing taking control of the former British colony, accompanied by a formidable layer of security as authorities showed little patience for pro-democracy protests. (Photo by Kin Cheung/AP Photo)

A reveller catches beer thrown from a balcony during the opening day or “Chupinazo” of the San Fermin Running of the Bulls fiesta on July 6, 2017 in Pamplona, Spain. The annual Fiesta de San Fermin, made famous by the 1926 novel of US writer Ernest Hemmingway entitled “The Sun Also Rises”, involves the daily running of the bulls through the historic heart of Pamplona to the bull ring. (Photo by Pablo Blazquez Dominguez/Getty Images)