A Sumatran Tiger looks at visiting children from it's enclosure during the ZSL London Zoo's annual stocktake of animals on January 5, 2015 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Dan Kitwood/Getty Images)

A Cambodian girl goes through the garbage dump looking for things to recycle in order to survive July 26, 2003 in Phnom Penh, Cambodia. Rampant corruption in this impoverished country has lead to extreme poverty with many Cambodians living below the poverty line. (Photo by Paula Bronstein/Getty Images)

NASA's DHC-3 Otter plane flies in Operation IceBridge-Alaska surveys of mountain glaciers in Alaska in this image released on September 18, 2014. Over the past few decades, average global temperatures have been on the rise, and this warming is happening two to three times faster in the Arctic. (Photo by Chris Larsen/Reuters/NASA/University of Alaska-Fairbanks)

People watch as workers inflate a near-10 metre high giant spider by Singaporean artist Jackson Tan in Singapore's Marina Bay financial district on February 6, 2017. The spider is one of several inflatable creatures that will form the Art-Zoo, a section created by Singaporean artist Jackson Tan for the iLight Marina Bay annual light-art festival in the city-state. (Photo by Roslan Rahman/AFP Photo)

A woman with a snake on her body, taken in Rio de Janeiro, Brazil, April 2017. A holistic therapist uses snakes to massage her clients – claiming it cures depression and even helps victims of abuse. Instead of traditional massaging techniques, Sarah Zaad uses up to six pythons and boa constrictors on brave customers who want to relax or be treated for mental disorders. The flamboyant therapist from Rio de Janeiro, Brazil believes her snakes have a magic touch, which can benefit people by massaging their bodies. (Photo by Kadeh Ferreira/Barcroft Images)

A competitor walks on tightrope during a performance in Taizhou, Zhejiang Province, China, May 7, 2016. (Photo by Reuters/China Daily)

Women look on as Sauber's German driver Pascal Wehrlein steers his car during the second practice session at the Monaco street circuit on May 25, 2017 in Monaco, three days ahead of the Monaco Formula 1 Grand Prix. (Photo by Andrej Isakovic/AFP Photo)

People walk along the Neva River at sunset in St.Petersburg, Russia, Tuesday, December 6, 2016. The temperature in St.Petersburg is –9C ( 15.8 °F). (Photo by Dmitri Lovetsky/AP Photo)