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)

David Sharp, an engineer with Lockheed Martin, displays the “Samurai Flyer”, an aviation design inspired by the maple seed, during the Association for Unmanned Vehicle Systems International Conference August 16, 2011 in Washington, DC. Lockheed Martin unveiled the new design and demonstrated vertical takeoff and landing, stable hover, and on-board video streaming of the aircraft during their demonstration. (Photo by Win McNamee/Getty Images)

The space shuttle Endeavour is transported to the California Science Center in Exposition Park from Los Angeles International Airport (LAX) in Los Angeles, California. (Photo by Kevork Djansezian)

Anything not recycled in industry is sold on stalls along the neighbouring highway in Sitakunda Beach, Bangladesh, February 2012. A look inside Bangladesh’s ship breaking yards reveal the brutal conditions workers are subjected to everyday. (Photo by Jan Møller Hansen/Barcroft Images)

Men use ropes to try and right a supply truck overloaded with wheat straw along a road in Dargai, in the Malakand district, about 100 miles northwest of Pakistan's capital Islamabad, on April 13, 2012. (Photo by Mian Khursheed/Reuters)

Customer Andreas Kroker looks at a 3D-printed figure of himself at the Twinkind 3D printing studio in Berlin, December 13, 2013. A 3D-printed likeness is produced by taking a 360 degree photographic scan of a person, which is then rendered into a 3D digital model and retouched to meet the requirements for printing. The printing machine uses this digital model to produce a high-resolution solid figure. Twinkind co-founder Timo Schaedel said, people often come to the session well-groomed, with fresh hair-cuts and their best clothes, “just as they used to do in the past, when they had their portrait taken in a photo studio”. (Photo by Thomas Peter/Reuters)

These jaw-some images show what its like to look inside the mouth of a tiger shark. Captured in amazing detail, the unique pictures show the alien-like anatomy of the shark and reveal rows upon rows of razor sharp teeth and white coloured gills. The incredible photographs were taken when a curious shark began to inspect the camera of British born photographer, Adam Hanlon, 46. After sensing electronic impulses omitted by Adams camera, the inquisitive creature began to gently mouth at the cameras housing allowing him capture the unusual perspective. (Photo by Adam Hanlon/Caters News)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)