Long Exposure pictures showing Mount Sinabung spewing out hot lava on August 2, 2017 in Karo, Indonesia. Sinabung located in North Sumatra Province roared back to life in 2010 for the first time in 400 years. After another period of inactivity it erupted once more in 2013, and has remained highly active since. (Photo by Albert Damanik/Barcroft Images)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

A woman holds newly designed Indonesia Rupiah banknotes after exchanging her old bills at a Bank Indonesia mobile bank in Jakarta, Indonesia December 19, 2016. (Photo by Fatima El-Kareem/Reuters)

With its huge eyes, comical name and diminutive size, Mark R. Smith’s image of a baby Hawaiian bobtail squid can’t help but raise a smile. A curiously endearing creature, the cephalopod is just 1.5cm across, its mantle cavity bearing more than a passing resemblance to a rather natty shower cap. But it is also a beautiful example of symbiosis – nature’s version of “I’ll scratch your back if you scratch mine” – for on the underside of the squid is a light organ which houses bioluminescent bacteria. The squid offers the bacteria protection and food, while the bacteria emit a glow – a handy trait that the squid uses to offset its silhouette, helping it to evade predators in the depths below. Mark R. Smith’s entry combines several images of a Hawaiian bobtail squid with different focus lengths to create a final picture with greater depth of field than normal. (Photo by Mark R. Smith/Wellcome Images/Macroscopic Solutions)

In this photo taken Wednesday, March 8, 2017, a hospitality staff member pose for photos near the shadow of a tall light pole near the Great Hall of the People where a plenary session of the National People's Congress is held in Beijing, China. (Photo by Ng Han Guan/AP Photo)

A U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)

Kaylee Cantler, 15, of Waynesboro, Pa., applies blush during a natural makeup exercise at a modeling camp at the Courtyard Marriott Hotel in McLean, Va., on Monday, August 17th, 2015. (Photo by Brittany Greeson/The Washington Post)

A reporter takes pictures of a soldier during the annual Han Kuang military exercise in Kinmen, Taiwan, September 7, 2015. Rustic Kinmen, with a population of less than 129,000, is a half-hour ferry ride to China, but it takes an hour to fly to major Taiwan cities. Just off its shores, glass-walled high-rises wink seductively from the booming mainland port of Xiamen in one of China's most prosperous provinces. (Photo by Pichi Chuang/Reuters)