Boys eat at a rubbish dump where they are collecting recyclable waste outside Yemen's Red Sea port city of Houdieda January 20, 2016. (Photo by Abduljabbar Zeyad/Reuters)

South Korea's Black Eagles aerobatics team performs an aerial display forming a Ying and Yang logo during the Singapore Airshow at Changi exhibition center in Singapore on February 16, 2016. (Photo by Roslan Rahman/AFP Photo)

Chinese conglomerate Tiens Group employers take photos while waiting to be served Paella in Madrid, Spain, Friday, May 6, 2016. The billionaire founder of Chinese conglomerate Tiens Group is treating 3,000 of his best salespeople to a traditional Spanish paella meal in a free Madrid trip that also includes a bullfight and a tour of King Felipe VI's Royal Palace. The smiling salespeople washed down their heaping plates of paella with sangria Friday at a mass spread of picnic tables in a riverside park during the event footed by Li Jinyuan and organized by China's U Tour travel company. (Photo by Paul White/AP Photo)

A hillside erupts in flame as a raging wildfire fire burns in Placerita Canyon in Santa Clarita, Calif., Monday, July 25, 2016. A raging wildfire that forced thousands from their homes on the edge of Los Angeles continued to burn out of control Monday as frustrated fire officials said residents reluctant to heed evacuation orders made conditions more dangerous and destructive for their neighbors. (Photo by Nick Ut/AP Photo)

An orangutan named “Pacquiao” dressed in a Santa Claus costume reacts as he joins an “Animal Christmas Party” at the Malabon zoo in suburban Malabon, north of Manila, Philippines Monday, December 21, 2015. The Malabon Zoo is one of the largest private collections of exotic and endemic animals in the Philippines. (Photo by Aaron Favila/AP Photo)

Handout photo issued by Easyart of an experimental motorcycle as an archive of weird and wacky innovations has been unearthed by an amateur historian as he trawled through a collection of images spanning the last 100 years. (Photo by Easyart/PA Wire)