Tour guides wearing traditional Chinese dress practice smiling by biting chopsticks at Qingming Grand-River Park in Kaifeng, central China's Henan Province on March 2, 2017, aiming to provide better service for visitors. (Photo by IPA Asia via ZUMA Wire)

(L-R) Playmate Victoria Silvstedt, Donald Trump and Melania Knauss at the Playboy 50th Anniversary celebration December 4, 2003 in New York City. (Photo by Peter Kramer/Getty Images)

Adolf Hitler (left), German Nazi politician, in a deck chair next to is niece Angela (Geli) Raubal – around 1930. (Photo by Ullstein Bild/Ullstein Bild via Getty Images)

Bride Ana Vallejos, wearing a traditional “Caporales” Andean outfit, is escorted by her parents to her wedding celebration, in La Paz, Bolivia, Saturday, December 12, 2020. As a measure to reactivate the economy, the Bolivian government lifted restrictions to help curve the spread of the new coronavirus. Sporting, religious and cultural events may take place publicly until mid-January. (Photo by Juan Karita/AP Photo)

Iranian bodybuilder Sharareh Nobahari, 30, assists her fitness trainees at a gym in Tehran, Iran on September 20, 2019. (Photo by Nazanin Tabatabaee/Reuters)

The geese in March, Cambs, UK on August 25, 2025. The family of around 20 white waterfowl have been a fixture in March, Cambs, for years and have made their mark by regularly waddling to the high street. (Photo by South West News Service)

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)

A woman drinks at a bars area in Clapham, after the reopening of commercial activities following the outbreak of the coronavirus disease (COVID-19), in London, Britain, July 4, 2020. (Photo by Hannah McKay/Reuters)