Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

“A Mothers Tail”. A baby cub pulls on his mother's tail to get attention. Photo location: Masai Mara, Kenya. (Photo and caption by Tori Marsh/National Geographic Photo Contest)

A plane is buffeted by the wind as it comes in to land at Leeds Bradford Airport as as flights were cancelled and commuters were warned they faced delays as winds reached nearly 90mph when Storm Doris battered many part of Britain. Thursday February 23, 2017. (Photo by Danny Lawson/PA Wire via AP Photo)

A woman cries as she stands next to house destroyed by the earthquake in the Pacific coastal town of Pedernales, Ecuador, Sunday, April 17, 2016. A magnitude-7.8 quake, the strongest since 1979, hit Ecuador flattening buildings, buckling highways along its Pacific coast and killing hundreds. (Photo by Dolores Ochoa/AP Photo)

Indian men stand around sword fish for sale at a harbour a harbour in Chennai on June 5, 2016, as fishermen return with their catch after a 45-day fishing ban on the east coast of India. Authorities in the southern Indian state of Tamil Nadu had imposed a 45-day ban on fishing by mechanised vessels to protect marine life, with only “country boats” operating within five nautical miles off the coast. (Photo by Arun Sankar/AFP Photo)

An art installation formed with milk churns, made by land art artist Gerard Benoit a la Guillaume, is seen at the Chenau de Mayen in the resort of Leysin, Switzerland August 7, 2015. More than 80 milk churns were placed between the Tour d'Ai and the Tour de Mayen summits at an altitude of 2,000 meters (6,561 feet) above sea level under the direction of the artist, to be photographed for his ongoing art project entitled “Milk churns without borders”. (Photo by Denis Balibouse/Reuters)

A chimpanzee bottle-feeds a lamb at Southam Zoo Farm in Warwickshire. The owners of the zoo, Mr and Mrs Clews, bring up many of the animals as their pets; the animals, are, as a result, of a friendly disposition. (Photo by Fox Photos/Getty Images). 23rd August 1968

Adele Clark, aged 8, looks at an animatronic Gallimimus dinosaur at the Natural History Museum on April 20, 2011 in London, England. The Age of the Dinosaur is a summer exhibition combining animatronic models, fossils and CGI film footage. (Photo by Matthew Lloyd/Getty Images)