“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)

Padaung ethnic women arrive to listen to the speech of Myanmar opposition leader Aung San Suu Kyi (not in picture), Chairwoman of the National League for Democracy (NLD) party, during Suu Kyi's first official election campaign at Demoso township of Kayah State, eastern Myanmar, 10 September 2015. Suu Kyi is on a three-day visit to Kayah State near the Thai-Myanmar border, as part of her first official election campaign. Myanmar political parties and candidates started their campaigns on 08 September ahead of the upcoming general election, which will be held on 08 November 2015. (Photo by Lynn Bo Bo/EPA)

Tourists pose for a selfie in Cancun, October 13, 2015. Cancun's transformation in the 1970s from a small Caribbean fishing village into a strip of nightclubs and high-rise hotels has reduced biodiversity and polluted water resources as infrastructure struggles to keep up. (Photo by Edgard Garrido/Reuters)

Two men help each other cross a street covered in deep mud in Copiapo, Chile, Thursday, March 26, 2015. Unusually heavy thunder storms and torrential rains that began on Tuesday have blocked roads, caused power outages and affected some 600 people on this normally dry region. (Photo by Aton Chile/Marcelo Hernandez/AP Photo)

A man jokingly poses with a new installation of British graffiti artist Banksy's art in New York, October 20, 2013. (Photo by Carlo Allegri/Reuters)

Meet the real beach babes: the herd of pigs that live a life of luxury paddling in the crystal clear waters of the Bahamas, on August 28, 2013. (Photo by Caters News)

An artist has discovered a bizarre way to create his work – by coating the feet of insects with paint who then crawl across the canvas creating intricate pieces of art. (Photo by Caters News)

A paper rhacophorus arvalis (farmland green tree frog) of Taiwan (R) is surrounded by paper pandas at an exhibition called “Pandas on Tour” at the National Theater in Taipei on February 24, 2014. Some 1,600 paper made pandas are on display, designed by French artist Paulo Grangeon. (Photo by Mandy Cheng/AFP Photo)