A tale of two foxes. Surprising behaviour, witnessed in Wapusk national park, on Hudson Bay, Canada, in early winter. Red foxes don’t actively hunt Arctic foxes, but where the ranges of two predators overlap, there can be conflict. Though the light was poor, the snow-covered tundra provided the backdrop for the moment that the red fox paused with the smaller fox in its mouth in a grim pose. (Photo by Don Gutoski/2015 Wildlife Photographer of the Year)

A girl holds a blossom in her mouth while posing for photos under cherry blossom trees at Wuhan University on March 11, 2021 in Wuhan, China. Tourists come to view cherry blossoms at the university during the spring. Wuhan University, first founded in 1893, is widely known as one of the most beautiful universities in China. (Photo by Getty Images/China Stringer Network)

“Secrets of the Whales”. Skerry’s photographs celebrate the lives and culture of whales, illuminating recent research and their diverse behaviours. His latest work focuses on four key species: sperm whales, humpbacks, orca and beluga whales. Humpback whales bubble-net feeding off the coast of Alaska. They work cooperatively to feed on herring by blowing a perfect ring of bubbles underwater to form a net encircling the fish. The whales then swim up through the centre of the bubble net with their mouths open. (Photo by Brian Skerry/National Geographic Photo/Visa pour l'Image)

A prong extending from a remote-controlled robot prototype approaches the mouth of a volunteer to extract a throat swab sample, as part of a self-funded project to assist physicians in running tests on suspected COVID-19 coronavirus patients in a bid to limit human exposure to disease-carriers, at a private hospital in Egypt's Nile delta city of Tanta, on March 20, 2021. (Photo by Khaled Desouki/AFP Photo)

Jacob's Well is a perennial karstic spring in the Texas Hill Country flowing from the bed of Cypress Creek, located northwest of Wimberley, Texas. The twelve foot (four meter) diameter mouth of the spring serves as a popular swimming spot for the local land owners whose properties adjoin Cypress Creek. From the opening in the creek bed, Jacob's Well cave descends vertically for about thirty feet (ten meters), then continues downward at an angle through a series of silted chambers separated by narrow restrictions, finally reaching a depth of one hundred and twenty feet (forty meters). Until the modern era, the Trinity Aquifer-fed natural artesian spring gushed water from the mouth of the cave, with a measured flow in 1924 of one hundred and seventy gallons per second (six hundred and forty liters per second) discharging six feet (two meters) into the air. The spring is the greatest source of water recharging the Edwards Aquifer.

This diver almost got sucked into the mouth of a massive whale shark as it feeds on plankton. But far from staring into the jaws of death – the shark, which are the sea's largest fish, is actually vegetarian. The relieved diver escaped from the encounter unscathed and continued to enjoy the presence of the incredibly docile animals. The stunning photograph, by Mauricio Handler, was taken during a feeding session where more than 600 of the huge creatures gathered to feed on tuna spawn. (Photo by Mauricio Handler/Daily Mail/Solent)

Bronze whaler shark (Carcharhinus brachyurus), caught in traditional seine net and released by fisherman, Muizenberg beach, Cape Town, South Africa on October 11, 2016. Action shots have captured fishermen trying to free a potentially deadly Bronze Whaler shark who was caught in their nets. The incredible images show the eight-foot-long 500-pound predator lunging its mouth towards the fishermen who are desperately trying to pull it back into the safety of the sea by its tail. Eventually they succeeded. (Photo by Chris and Monique Fallows/NPL)

Photographer Lucy Ray says she has been scratched by the pooches who are diving underwater to try and catch a tennis ball. Their wide-eyed desperation has been captured by a specialist underwater photographer who admits she has been bitten and scratched by the pooches who only had eyes for the ball. Lucy Ray, 34, said: “A dog could have the cutest face on land but as soon as they get in the water they can be terrifying. Their eyes bulge and teeth shoot out of their mouth just like an alien as they try to catch the ball”. (Photo by Lucy Ray)