A group of hikers atop Mount St. Helens on July 21, 2016. Mount St. Helens or Louwala-Clough is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is 96 miles south of Seattle, Washington, and 50 miles northeast of Portland, Oregon. (Photo by Raxit Kagalwala)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

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)

Buddy Mae Walker (R), 4, looks at herself in the mirror while trying on a child respirator provided by the non-profit TeamRaccoonPDX on October 6, 2020 in Portland, Oregon. We told them their grandparents sent them space suits to keep them safe, Jessica Walker said of the respirators, which the family sought out after police used tear gas near their residential street. (Photo by Nathan Howard/Getty Images)

A police officer speaks to a driver shortly after midnight in Bucharest, Romania, Monday, November 9, 2020 informing him of the pandemic related night traffic restrictions that just came into effect. Romania introduces new restrictions aimed at limiting the spread of the COVID-19 infections following a week when it registered an all time high number of new infections. (Photo by Vadim Ghirda/AP Photo)

Health workers watch as the vaccine against the Coronavirus arrives at a nursing home in l'Hospitalet de Llobregat in Barcelona, Spain, on Sunday, December 27, 2020. The first shipments of coronavirus vaccines developed by BioNTech and Pfizer have arrived across the European Union, authorities started to vaccinate the most vulnerable people in a coordinated effort on Sunday. (Photo by Emilio Morenatti/AP Photo)

Fans react as they watch HBO's “Game of Thrones” series finale at a viewing party at Brennan's bar in Marina del Rey, California, May 19, 2019. (Photo by Robyn Beck/AFP Photo)

The Canary Wharf financial district stands in London, Britain on August 11, 2019. (Photo by Simon Dawson/Reuters)