PETA (People for the Ethical Treatment of Animals) activists wear crocodile masks during a demonstration against the use of crocodile skins ahead of Milan's Fashion Week, in Milan's Duomo Square, Italy, Tuesday, February 21, 2017. Milan Fashion Week opens Wednesday. (Photo by Antonio Calanni/AP Photo)

Take me away, deer, Russia. The Nenet people of Arctic Russia use reindeer and sledges as a prime mode of transport. The animals’ navigational ability means that in severe conditions they are sometimes the only hope of survival. (Photo by Kamil Nureev/Smithsonian Photo Contest)

Brittnai of El Paso, Texas, USA, performs in the Professional Division Competition during the 5th Annual US Pole Dance Championship on April 1, 2017 at the Symphony Space Theater in New York City. (Photo by Timothy A. Clary/AFP Photo)

A US Army M1A2 SEP tank participates in the Strong Europe Tank Challenge 2017 at the military training area in Grafenwoehr, Germany, 12 May 2017. Six North Atlantic Treaty Organization (NATO) nations and partner nations, Austria, France, Germany, Poland, Ukraine and the USA are taking part in this competing exercise. (Photo by Christian Bruna/EPA)

A worker manually changes the direction of the bonde, the typical tram line in Santa Teresa neighborhood, using a rope in Rio de Janeiro, Brazil, September 9, 2015. The Santa Teresa bonde, called “Bondinho” in Portuguese, is running with passengers as a part of a test period, after the service was suspended in 2011 following an accident that killed six people, according to residents. (Photo by Pilar Olivares/Reuters)

A videographer uses a drone as he takes a video of a model presenting a lingerie creation at the rehearsal for Eve's Temptation collection during China Fashion Week in Beijing, October 26, 2014. (Photo by Kim Kyung-Hoon/Reuters)

Pedestrians stop to look at and photograph a DeLorean Motor Company DMC-12 customized to look identical to the car used in the film "Back to the Future Part II" and that will be part of a Lyft promotion in New York, October 21, 2015. In the 1989 movie, main character Marty McFly traveled to the future to October 21, 2015. (Photo by Lucas Jackson/Reuters)

Two attendees compete in the biggest vape cloud competition at the Vape Summit 3 in Las Vegas, Nevada May 2, 2015. According to new research provided to Reuters, youngsters say that performing tricks is one of the top two reasons they began using e-cigs. (Photo by David Becker/Reuters)