Animal rights activists covered with fake blood sit on the floor during a protest against the use of animals in research to mark World Day for Animals in Laboratories in central Madrid April 24, 2014. The sign reads, “How many rabbits do your shampoo kill?”. (Photo by Andrea Comas/Reuters)

Buyan, a male Siberian brown bear, is given a shower by a zoo employee in his enclosure at the Royev Ruchey zoo in Russia's Siberian city of Krasnoyarsk June 24, 2014. The Siberian city has been experiencing temperatures of around 30 degrees Celsius over the last week. (Photo by Ilya Naymushin/Reuters)

Two stags fight in a wildlife park in Aurach near Kitzbuehel, in the Austrian province of Tyrol. (Photo by Kerstin Joensson/Associated Press)

A technician holds a recently 3D printed replica of Darth Vader's melted helmet from “Star Wars: The Force Awakens”, in the Propshop headquarters at Pinewood Studios near London, Britain May 25, 2016. Propshop headquarters at Pinewood Studios is making limited edition replicas of Star Wars props. (Photo by Peter Nicholls/Reuters)

Young U.S. visitors pose for a photograph next to a vintage car in Havana March 16, 2016. (Photo by Ueslei Marcelino/Reuters)

People in costume take photos during a Halloween event on October 31, 2015 in Lan Kwai Fong, Central District, Hong Kong. Halloween, a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Jerome Favre/Getty Images)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

Tourists ride a cable car in the form a of a Chiva, a bus used to serve rural routes, in Pitalito, Colombia, Tuesday, April 5, 2017. The ride called “La Chiva Voladora” costs about $0.70 and you zip along about 800 meters from one side of a hill to another. (Photo by Fernando Vergara/AP Photo)