This family of warthogs regularly visited our campsite in the Ethiopian highlands so I set up a remote camera with a wide-angle lens to photograph them as they rummaged around for food. They just had a mud bath. (Photo by Will Burrard-Lucas/Caters News Agency)

Amundsen-Scott South Pole Station experiences months of darkness. The sun dips below the horizon on March 21, after which follows several weeks of twilight before complete darkness results. Photo taken on June 25, 2009. (National Science Foundation/Jeremy Johnson)

A Hawaiian cleaner wrasse provides its cleaning services to a yellowfin goatfish in a reef community off the Big Island in Hawaii. Cleaner species help rid their hosts of ectoparasites, dead tissue, bacteria and fungi. Studies have shown cleaning to play a vital role in keeping many reef ecosystems healthy. (Photo by Marty Snyderman/Caters News Agency)

Performers dressed as Ded Moroz, the equivalent of Santa Claus, and his granddaughter Snegurochka (Snow Maiden) take on shoe covers as they visit the Republican Scientific and Practical Centre of Pediatric Surgery in Minsk, Belarus, December 28, 2016. (Photo by Vasily Fedosenko/Reuters)

Female members of the Chinese People's Liberation Army (PLA) honour guard stand behind a string to ensure that they are in a straight line before a welcoming ceremony for Russian President Vladimir Putin outside the Great Hall of the People in Beijing, China, June 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

These are the stunning images of what looks like a picturesque winter wonderland – but actually shot in the middle of summer. Amateur photographer Catherine Perkinton, 45, has spent the summer travelling around the country to create the fabulous images by utilising infra-red. (Photo by Catherine Perkinton/SWNS/ABACAPress)

Miss Universe contestant Carolina Duran of Costa Rica, center, reacts to a TV network's drone as others prepare to pose from the deck of the yacht Happy Life prior to cruising to a beach resort in Batangas province Thursday, January 19, 2017 at the Philippine Navy headquarters in Manila, Philippines. Eighty-six candidates from around the world are vying for the title to succeed Pia Wurtzbach from the Philippines. The competition takes place on Jan. 30. They are, from left, Cherell Williamson of Bahamas, Rebecca Rath of Belize, Hildur Maria of Iceland, and Chanelle de Lau of Curacao. (Photo by Bullit Marquez/AP Photo)

An Afghan man is carried out of a hospital after receiving treatment following a suicide truck bomb attack in Kabul, Afghanistan August 7, 2015. The bombings were the first in Kabul since Mullah Akhtar Mansour took charge of the Taliban last week, and followed a rare truck bomb attack in an eastern province on Thursday. (Photo by Omar Sobhani/Reuters)