A large bull walrus returns to the shores of Prins Karl Forland after diving and feeding on clams. (Photo by Paul Nicklen/National Geographic). Svalbard, Norway, 2011

Scientists have captured these images in laboratories during research into what makes our daily food. Photo: Blueberry. (Photo by SPL/Barcroft Media)

Members of the Apollo Rainbow Dancers stretch out in special A train late on May 4, 1985, in New York. The legendary Apollo Theatre celebrated its 50th anniversary in an official reopening after a 15 month refurbishing with a celebrity studded evening. (Photo by Ray Stubblebine/AP Photo)

A couple chats at a park during sunset in Chihuahua November 15, 2014. (Photo by Jose Luis Gonzalez/Reuters)

Fresh produce and baskets of fish surround a woman at the Siti Khadijah market in Kota Bharu, Malaysia. (Photo by Duratul Ain D.)

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)

A diver dressed in a Santa Claus costume performs with sardines at the Coex Aquarium in Seoul, South Korea, Wednesday, December 9, 2015. (Photo by Ahn Young-joon/AP Photo)

A Vietnamese woman, wearing the traditional “ao dai” long dress, poses for photos along peach blossom flowers ahead of the Vietnamese “Tet” (Lunar New Year festival), in a field in Hanoi, Vietnam, February 2, 2016. (Photo by Reuters/Kham)