In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

Dr. Anton Lim is interviewed by the media as he holds Kabang, a two-year-old injured mixed breed, upon arrival at the Ninoy Aquino International Airport in Pasay city, south of Manila, Philippines, early Saturday June 8, 2013 from San Francisco, Calif. Kabang lost her snout and upper jaw saving two girls' lives in the Philippines was headed back to its owner following treatment at the University of California, Davis veterinary hospital. (Photo by Bullit Marquez/AP Photo)

Miss Georgia USA Emanii Davis, Miss Kentucky USA Kyle Hornback and Miss North Carolina USA Devin Gant competes in the swimsuit competition during the 2016 Miss USA pageant preliminary competition at T-Mobile Arena on June 1, 2016 in Las Vegas, Nevada. The 2016 Miss USA will be crowned on June 5 in Las Vegas. (Photo by Ethan Miller/Getty Images)

Father Christmas arriving at the Arding and Hobbs store in Clapham Junction, London, 2nd November 1926. (Photo by H. F. Davis/Topical Press Agency/Getty Images)

“After an afternoon of hiking and exploring the caves of Rhossili Bay, West Glamorgan, we caught the sun breaking through the clouds”. (Photo by Megan Warren-Davis/The Guardian)

A rail worker fixing a fog warning notice at South Woodford Railway Station in Essex. (Photo by H. F. Davis/Topical Press Agency/Getty Images). 20th October 1938