The double compound eyes of a male St. Mark's fly (Bibio marci), submitted by Dr. David Maitland from Feltwell, UK. (Dr. David Maitland)

A woman sits in a train at a subway station in Pyongyang, North Korea on September 11, 2018. (Photo by Danish Siddiqui/Reuters)

Young people wearing no pants participate in the “No Pants Subway Ride” in New York City, 13 January 2019. No Pants Subway Ride is an annual global event started in New York, USA in 2002. (Photo by William Volcov/ZUMA Press)

London Mayor Boris Johnson takes part in a tug of war with members of the armed services to launch the London Poppy Day, outside City Hall, in London, October 27, 2015. London Poppy Day is a street collection event to raise money for serving and retired members of the armed services and their families. (Photo by Stefan Wermuth/Reuters)

Children sit under a crocodile based table, as they pose for photographers during a press preview of a themed auction that features the animal as artistic inspiration, entitled “Creatures Great and Small”, in London, Monday, December 15, 2014. The sale scheduled for December 17, 2014, explores animals across a diverse range of mediums and styles, from intricate carving details in 19th century furniture through to contemporary sculpture, according to Christie’s auction house. (Photo by Lefteris Pitarakis/AP Photo)

A woman travels on a train stopping at a subway station visited by foreign reporters in central Pyongyang, North Korea on April 14, 2017. (Photo by Damir Sagolj/Reuters)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

Each year Nikon Small World recognizes the excellence of photography taken under the microscope. The contest showcases the beauty and complexity of life. Anyone interested in microscopy and photography can enter the contest and in its 42nd year, Nikon Small World received 2,000 entries from 70 countries. Here: 11th Place; Scales of a butterfly wing underside (Vanessa atalanta). (Photo by Francis Sneyers/Nikon's Small World 2016)