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)

Police officers standby while a forest fire burns the hills of Valparaiso city, northwest of Santiago, March 13, 2015. Several hectares of land has been burned due to forest fires near Valparaiso city, with no report of deaths or injuries, local authorities said. (Photo by Lucas Galvez/Reuters)

A replica of pre-historic drawings showing horses, rhinoceros and aurochs is seen on a wall during a press visit at the site of the Cavern of Pont-d'Arc project in Vallon Pont d'Arc April 8, 2015. The Cavern of Pont-d'Arc project is a replica of the pre-historic Decorated Cave of Pont-d'Arc known as Grotte Chauvet, in Vallon Pont-d'Arc in the Ardeche region, containing the world's earliest known art which was recently named a UNESCO World Heritage site. The facsimile cavern, which condenses some 8000m² of the original site into 3000m², will display faithful reproductions of paintings and engravings and will be inaugurated on April 10 and will open to the public on April 25. (Photo by Robert Pratta/Reuters)

A man rows a boat on the Dal Lake as a woman holds an umbrella during snowfall in Srinagar February 19, 2015. (Photo by Danish Ismail/Reuters)

A Libyan fireman stands in front of smoke and flames rising from an oil storage tank at an oil facility in northern Libya's Ras Lanouf region on January 23, 2016, after it was set ablaze earlier in the week following attacks launched by Islamic State (IS) group jihadists to seize key port terminals. (Photo by AFP Photo/Stringer)

An airplane house is pictured in the village of Miziara, northern Lebanon May 12, 2015. Miziara prides itself on building residential homes that resemble ancient Greek temples and Egyptian ruins, one is even built in the shape of an Airbus A380. (Photo by Aziz Taher/Reuters)

Roman Amoyan of Armenia, bottom, and Elman Mukhtarov of Azerbaijan compete in the the Men's wrestling, 59kg Greco-Roman Bronze Medal event at the 2015 European Games in Baku, Azerbaijan, Saturday, June 13, 2015. (AP Photo/Dmitry Lovetsky)

Farmers use tractors and burn tires, hay and manure as they block the highway between Morlaix and Brest during a demonstration against the market prices of their product, on July 22, 2015 in Morlaix, western of France. French farmers protesting over falling food prices threatened to step up blockades of cities, roads and tourist sites, as the government prepared to unveil emergency aid for them. Farmers have dumped manure in cities, blocked access roads and motorways and hindered tourists from reaching Mont St-Michel in northern France, one of France's most visited sites. (Photo by Fred Tanneau/AFP Photo)