Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, Hungary, June 14, 2016. Millions of these short-lived mayflies engage in a frantic rush to mate and reproduce before they perish in just a few hours during “Tiszaviragzas” or Tisza blooming season from late spring to early summer every year. (Photo by Laszlo Balogh/Reuters)

Serge Huguenin of the Blondeau foundry takes the newly melted bell out of the mould in La Chaux-de-Fonds, Switzerland January 21, 2016. At this year's Summer Olympics in Rio de Janeiro, no matter how elaborate the opening ceremony or how sophisticated the live broadcasts, the final lap of athletics races will be announced the traditional way by ringing an old-fashioned bell. Omega, the official timekeeper of the event, has ordered 21 bells, forged almost entirely by hand by Blondeau's Bell Foundry in the Jura Mountains in Switzerland. Each last-lap bell is branded with the RIO 2016 logo and circled with the words “2016 GAMES OF THE XXXI OLYMPIAD”. (Photo by Denis Balibouse/Reuters)

In northwest Russia, in a small village called Alekhovshchina, Nadia Sablin's aunts spend the warmer months together in the family home and live as the family has always lived, chopping wood to heat the house and making their own clothes. Sablin's book of photographs, “Aunties: The Seven Summers of Alevtina and Ludmila”, is published by Duke University Press. Here: “Two-Handed Saw, 2014”. (Photo by Nadia Sablin)

“Centuries ago, Inuit hunted the bowhead whale. At that time, whale hunting undoubtedly was part of a complex and very important ritual, if only because of the size of the catch. The position that the ancestors of today's Inuit occupied in the living world involved a relationship with the spirit that inhabited each animal but also their species”. (Photo by Robert Frechette/2014 Sony World Photography Awards)

These unique photos capture the moment a boy has his teeth picked clean by amazing underwater shrimp. These fascinating creatures spend their lives diving inside the mouths of fish to remove the parasites that lurk there. Russell Laman imitated the behaviour of the surrounding fish swarm to entice the cleaner shrimp into his mouth whilst snorkelling with his father Tim Laman in Bali, Indonesia. The 13-year-old queued with the waiting fish and then opened his mouth when the shrimps came near. (Photo by Tim Laman/Caters News)

You might feel as if you are being watched when you look at these incredible pictures – revealing the close-up world of a spider's eyes. The intimidating creatures, which look like they should live in a horror film, star menacingly at the camera as every fleck of colour and hair are revealed. But despite their appearance the arachnids are actually jumping spiders, which measure a tiny six millimetres in length. The harmless arachnids, which are capable of jumping up to six times their own height, can be found in grassy meadows and on the walls of houses on sunny days. (Photo by SWNS/ABACA Press)

“7584 Fish”. On a windy day right after a Cyclone passed the far northern Great Barrier Reef i took some friends out to the reef. Never before i saw that many glass fish on this particular coral “bommie”. Just when i setup my camera, this Napoleon Wrasse swam right through the school of fish building a living frame. Photo location: Cairns, Great Barrier Reef, Flynn Reef, Australia. (Photo and caption by Christian Miller/National Geographic Photo Contest)