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)

Athletes from Australia's Olympic team going to the 2016 Olympics in Rio present their uniforms alongside Brazilian Samba dancer Sashya Jay at an official unveiling ceremony at Sydney's Bondi Beach, March 30, 2016. (Photo by Jason Reed/Reuters)

Inflatable dolls in the shape of ducks are seen in front of the National Congress during a protest against tax increases in Brasilia, Brazil, March 29, 2016. The campaign “I will not pay the Duck” is organized by the Federation of Industries of Sao Paulo (FIESP) and uses the duck symbol in reference to industries that pay high taxes. (Photo by Gregg Newton/Reuters)

This green-skinned trio were happy to pose for the camera – with one little frog smiling happily for its close up. The three Reinwardt's Flying Frog, commonly known as the black webbed tree frog or the green flying frog, were spotted playing in a tree by photographer Hendy Mp. The 25-year-old who saw the frogs near his home in Sambas, Kalimantan Barat, in Indonesia, said they reminded him of three brothers playing together. (Photo by Hendy Mp/SOLENT News)

Commonwealth dance group on the right track with Virgin Trains – Photo call at Glasgow Central Station. (Photo by Daily Record)

The Northern Lights glow green in a spectacular light show above a field of trees frozen solid with snow. (Photo by Jaak Sarv/Solent News & Photo Agency)

Two young women, having enjoyed a drink at a party, dance together in Tehran, Iran. Although unrelated men and women are forbidden to socialise together many people ignore these strictures in the privacy of their own homes. (Photo by Hossein Fatemi/Reuters/Panos Pictures/Courtesy of World Press Photo Foundation)

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/AP Photo)