Partipants vie for the ball during the 11th Mud Olympics held at the North Sea coast in Brunsbuettel, Germany, July 11, 2015. Amateur athletes have competed in several disciplines at the Mud Olympics since 2004. (Photo by Axel Heimken/EPA)

A busy rush hour sees thousands of commuters climbing on board a train – as well as holding onto its sides and sitting on the roof before it speeds off. Men, women and children climb and are pulled up onto the roof of the train, which is around 12ft (3.6m) high, as they try to find themselves a space. With no seats available inside, many commuters decide to take the risk and choose a rooftop view for their journey out of Dhaka city, in Bangladesh. (Photo by Yousuf Tushar/Solent News & Photo Agency)

Turkana tribesmen walk with guns in order to protect their cattle from rival Pokot and Sambur tribesmen near Baragoy, Kenya February 14, 2017. Cattle rustling and competition for grazing have long troubled northern Kenya, but severe drought and political rivalries ahead of the elections have exacerbated the situation between ethnic tribes. (Photo by Goran Tomasevic/Reuters)

“This cheeky polar bear tried to hitch a lift off an unsuspecting driver by clambering into the back of his pick-up truck. The curious creature spent about half an hour inspecting the vehicle and its owner before casually trying to climb aboard. However, the truck must not have been up to scratch because the 7ft bear, weighing approximately 300lbs, promptly jumped back out and sauntered off”. – Barcroft Media. Photo: “Awright mate, any chance of a lift to the North Pole?” (Photo by Steven Kazlowski/Barcroft Media)

A participant has his body painted before a regional bodybuilding championship in Stavropol, southern Russia, April 10, 2016. (Photo by Eduard Korniyenko/Reuters)

A man rides his bicycle as a wave crashes at La Libertad malecon on May 13, 2015. El Salvador emergency authorities has declared an orange alert along the Pacific coast due to a large swell that affected the Salvadoran coast. The swell originated from the extra-tropical storms that formed in New Zealand and the Southern hemisphere, according to El Salvador's Ministry of Environment and Natural Resources. (Photo by Jose Cabezas/Reuters)

In this January 25, 2013 photo, snake handler Saintilus Resilus holds a snake in front of his lips as he trains the snake to recognize his smell as he prepares for his street performances during the pre-Lenten Carnival season, at his home in Petionville, Haiti. Resilus sees himself as something of a performance artist, showing off with snakes and other animals that Haitians don't see every day, earning tips from impromptu audiences. (Photo by Dieu Nalio Chery/AP Photo via Matt Dayhoff)