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)

A young girl gives a banana to a tamed baboon on the outskirts of Beira, Mozambique, Sunday, March, 31, 2019. Cholera cases among cyclone survivors in Mozambique have jumped to 271, authorities said. So far no cholera deaths have been confirmed. (Photo by Tsvangirayi Mukwazhi/AP Photo)

Chinese artist Zhou Jie takes a nap on an unfinished iron wire bed, one of her sculpture works, after lunch as a friend of hers looks on at Beijing Now Art Gallery, in Beijing August 11, 2014. Zhou started her art project titled “36 Days” on August 9, in which she would live inside an exhibition hall with an unfinished iron wire bed, some iron wire sculptures in the shape of stuffed animal dolls, a certain amount of food and her mobile phone, for 36 days. The entire process is open to visitors and she may also interact with them, according to Zhou. (Photo by Jason Lee/Reuters)

In this May 1, 2016 photo, a reluctant donkey is alternately pushed and pulled and enticed with carrots toward town hall in order to be dressed for the costume competition at the annual donkey festival in Otumba, Mexico state, Mexico. Otumba was an important donkey market during Spanish colonial times, standing at the crossroads of major roads leading to Mexico City, where the beasts pulled heavy loads and carried travelers. Today, however, farmers use tractors and pickup trucks, and the donkey population is in decline. (Photo by Rebecca Blackwell/AP Photo)

Peruvian surfer Domingo Pianezzi rides a wave with his alpaca Pisco at San Bartolo beach in Lima March 16, 2010. Pianezzi has spent a decade training dogs to ride the nose of his board when he catches waves, and now he is the first to do so with an alpaca. (Photo by Pilar Olivares/Reuters)

Artists from the Beijing Dance Academy perform to celebrate the Chinese Lunar New Year in Budapest, capital of Hungary, February 6, 2019. (Photo by Attila Volgyi/Xinhua News Agency/Barcroft Media)

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 postman walks past an art work titled “Alphabetti Spaghett” by artist Alex Chinneck on Norborough Road in Sheffield, Yorkshire, England on September 26, 2019. (Photo by Danny Lawson/PA Images via Getty Images)