A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Models walk the runway at the annual Victoria's Secret fashion show at Earls Court on December 2, 2014 in London, England. (Photo by Tim P. Whitby/Getty Images)

A woman jumps as a friend (not seen) takes a photo in front of a large drawing of Pope Francis depicting him as a superhero near the Vatican January 29, 2014. The Argentinian Pope is shown taking off into air with his right fist clenched in a classic Superman style. (Photo by Alessandro Bianchi/Reuters)

In this April 28, 2014 file photo, a woman throws a rock and a bag at police blocking her from getting home in the Huepetuhe district of the Madre de Dios region of Peru. Security forces began destroying illegal gold mining machinery in Peru's southeastern jungle region of Madre de Dios, as authorities began enforcing a ban on illegal mining. (Photo by Rodrigo Abd/AP Photo)

Recording artists Demi Lovato (L) and Iggy Azalea perform on the Pepsi Stage, during the 2015 MTV Video Music Awards, at The Orpheum Theatre on August 30, 2015 in Los Angeles, California. (Photo by Frederick M. Brown/Getty Images for MTV)

People follow king penguins exploring their outdoor pen, during a so-called “penguin parade”, when the animals walk outside their enclosure and the visitors can walk behind them, at Zurich's Zoo in Zurich, Switzerland January 28, 2017. (Photo by Arnd Wiegmann/Reuters)

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 staff member sets up a ROBOTLEO robot at the Global Mobile Internet Conference (GMIC) 2017 in Beijing, China April 28, 2017. (Photo by Jason Lee/Reuters)