Long-tailed mayflies (Palingenia longicauda) at Tisza river near Tiszainoka 135km (84 miles) southeast of Budapest, June 23, 2013. 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)

A baby rhesus macaque (Macaca mulatta) looks up as it plays with a tiger cub at a zoo in Hefei, Anhui province, August 2, 2012. (Photo by Jianan Yu/Reuters)

The Enemy, 1944. With the outbreak of world war two, photojournalism was enlisted in defence of Mother Russia. In this photo by Anatoli Egorov, who was wounded in action, corporal Stepan Vasiljevich Ovcharenko shoots at enemy troops with a machine gun. (Photo by Anatoli Egorov/Lumiere Brothers Center for Photography)

Deputies of the opposition fight with deputies of the majority for a second time in two days, during the second session of the newly elected Ukrainian parliament in Kiev on December 13, 2012. (Photo by Sergei Supinsky/AFP Photo)

“Tardigrades (commonly known as waterbears or moss piglets) are small, water-dwelling, segmented animals with eight legs. Tardigrades were first discovered in 1773 by Johann August Ephraim Goeze, who called them kleiner Wasserbär, meaning “little water bear” in German. The name Tardigrada means “slow walker” and was given by Lazzaro Spallanzani in 1777. The name water bear comes from the way they walk, reminiscent of a bear's gait. The biggest adults may reach a body length of 1.5 millimetres (0.059 in), the smallest below 0.1 mm. Freshly hatched tardigrades may be smaller than 0.05 mm”. – Wikipedia. Photo: Tardigrades. (Photo by SPL/East News)

Competitors release their hens during the World Championship Hen Racing Championships in Bonsall, Britain August 1, 2015. (Photo by Darren Staples/Reuters)

These hyper realistic drawings are so lifelike they could pass for photographs. The incredibly detailed works of art were created by self-taught artist Ivan Hoo, from Singapore, who earns a living from his realistic drawings and paintings. The 31-year-old takes up to three days to complete the impressive pieces, which include animal portraits and still life drawings of everyday items such as a Starbucks cup. The A3 sketches are completed using a range of soft pastel pencils and are drawn from still life, or a photograph taken by Ivan himself. Here: Ivan Hoos drawing of a pug. (Photo by Ivan Hoo/Caters News)

“Romantic”. A brown bear in Martinselkonen, Finland. (Photo by Valtteri Mulkahainen/Comedy Wildlife Photography Awards)