Two race pigs jump over an obstacle during a rural festivity in reference to Maria Ascension in San Bernardino, Switzerland on Monday, August 15 2016. (Photo by Samuel Golay/Keystone/TI-Press via AP Photo)

A student participates in celebrations ahead of the Janmashtami festival, which marks the birth anniversary of Lord Krishna in Mumbai, India, August 23, 2016. (Photo by Danish Siddiqui/Reuters)

Participants wearing historical attire compete on historical high wheel Penny Farthing bicycles in the traditional 'One Mile Race' at Letna Park in Prague, Czech Republic, November 7, 2015. The meeting of Penny Farthing bicycles is taking place for the 22th time. (Photo by Filip Singer/EPA)

“Winter Climbing from inside Ben Nevis”. The view from inside the mountain, as a winter climber passes through the cave on Minus Three gully. Photo location: Ben Nevis, Fort William, Scotland. (Photo and caption by Daniel Wildey/National Geographic Photo Contest)

Five year old George holds an orange to feed the Owl butterflies at the Natural History Museum in London, Thursday, March 30, 2017. Hundreds of tropical butterflies were released to launch the Natural History Museum's Sensational Butterflies exhibition, starting for the public on March 31, 2017. (Photo by Frank Augstein/AP Photo)

TV and radio host Lizzie Cundy, 46, attends the World Premiere of “The Hatton Garden Job” at The Curzon Soho on April 11, 2017 in London, England. (Photo by Fame Flynet)

St Andrews University students skinny dip in the sea as May Day celebrations in St Andrews, Scotland on April 30, 2017. Hundreds of revellers ditched their clothes and bravely jumped into the bitterly cold North Sea. (Photo by Alamy Stock Photos)

The car driven by Scott Dixon, of New Zealand, goes over the top of Jay Howard, of England, in the first turn during the running of the Indianapolis 500 auto race at Indianapolis Motor Speedway, Sunday, May 28, 2017, in Indianapolis. (Photo by Marty Seppala/AP Photo)