“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

“Double head vulture”. On the day of windy days during raptors migration some people in my country start to catch these tired raptors, so in this day we go to photograph some raptors and we saw these tow tired vultures, so we start to drag them away from the hunters until they reach a good hidden place, to make them safe until they start a new journey. Photo location: Kuwait. (Photo and caption by Mohd Khorshed/National Geographic Photo Contest)

Pakistani youths cool off in a stream during hot weather on the outskirts of Islamabad on April 29, 2016. Pakistan's Meteorological Department has forecast hot and dry weather in most parts of the country with the highest temperatures recorded at 41 celsius in the southern Sindh province. (Photo by Aamir Qureshi/AFP Photo)

A biker shows his 12-year-old cat “Chiquinho” – which always rides with him on his motorbike – in Rio de Janeiro, Brazil, on June 19, 2016. (Photo by Yasuyoshi Chiba/AFP Photo)

A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)

Mark Dill and Brit Thacker practice acro-yoga as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. August 29, 2016. (Photo by Jim Urquhart/Reuters)

(Top L-R) Playboy Playmates Anna Sophia Berglund, Kayla Rae Reid, Dominique Jane, Heather Rae Young, Alexandra Tyler, Val Keil, (bottom L-R) Audrey Aleen Allen, Ashley Doris, Hiromi Oshima, and Shanice Jordyn attend the Playboy Midsummer Night's Dream party at the Marquee Nightclub at The Cosmopolitan of Las Vegas on August 27, 2016 in Las Vegas, Nevada. (Photo by David Becker/Getty Images for Playboy Enterprises)

The jewelled flower mantis, commonly found in Asia, is believed to be the inspiration for many martial artists is seen in Jakarta, Indonesia on August 2, 2016. (Photo by Prabu Dennaga/Barcroft Images)