“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

A man crosses Canal Street in the wind and rain from Hurricane Isaac August 29, 2012. (Photo by David J. Phillip/Associated Press)

Aiden Haas, left, and Lilli Alcala pose after being crowned Mud King and Mud Queen at the 29th annual Mud Day, Tuesday, July 12, 2016 in Westland, Mich. The event, open to children 12 and younger, was at the Hines Park-Nankin Mills Area west of Detroit. Children 12 and younger were able to slosh around in the pit while participating in mud limbo, wheelbarrow races and other free activities. (Photo by Carlos Osorio/AP Photo)

Law enforcement officers clash with protesters, Wednesday, July 20, 2016, in Cleveland, during the third day of the Republican convention. (Photo by John Minchillo/AP Photo)

A man washes his horse as a woman bathes her son at concrete water pens under a flyover in a slum area in Kolkata, India October 21, 2016. (Photo by Rupak De Chowdhuri/Reuters)

Emma the Maltese's fur blows in the wind as she rides in her owner's purse on 5th Avenue at Central Park in New York December 2, 2014. (Photo by Carlo Allegri/Reuters)

Kamchatka brown bears at Kurile Lake in Kamchatka peninsula’s volcanic terrain, Russia on August, 2017. Kamchatka brown bears are generally not dangerous to humans, and only 1% of encounters result in attack. (Photo by Igor Ivanko/Anadolu Agency/Getty Images)

Members of the Baby Dolls, a traditional Mardi Gras social club, dance during a second line parade honoring music legend Fats Domino, in New Orleans, Wednesday, November 1, 2017. The thousand-strong group marched and danced from Vaughn's Lounge to Domino's former home in the Lower 9th Ward. Domino, a New Orleans native, died this past week. (Photo by Gerald Herbert/AP Photo)