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)

Dan surrounded by seven days of her own rubbish in Pasadena, California. If you've never thought about how much rubbish you throw away an honest photographic series will open your eyes. Men, women, couples and families with young children have been photographed lying on their backs surrounded by a week's worth of their own rubbish – from old cartons of milk, used nappies and even tampons. The startling series “Seven Days of Garbage” by Californian photographer Gregg Segal is an unforgettable reminder of the amount of waste a human collects in just seven days. (Photo by Gregg Segal/Barcroft Media)

“Don't Leave Any Food On Your Plate”. The giraffes at Nairobi's Giraffe Manor are totally at home with humans. They will eat out of your hand, or even off your plate. Photo location: Giraffe Manor, Nairobi, Kenya. (Photo and caption by Gavin Werbeloff/National Geographic Photo Contest)

Desk Safari is a new office phenomenon where you align your coworker’s head with an animal body on your desktop and take a photo. This is especially amusing if your coworker isn’t aware of what’s going on.

“Eye of the Tower” by Mehmet Yasa; Verona, Italy. “The staircase and the bell looks like an eye. Architecture can fascinate us in many ways”. (Photo by Mehmet Yasa/Art of Building Photography Awards 2017)

Desk Safari is a new office phenomenon where you align your coworker’s head with an animal body on your desktop and take a photo. This is especially amusing if your coworker isn’t aware of what’s going on.

In this April 4, 2017 photo, Zoologist Martha Llanes caresses baby chimpanzee Anuma II, left, while Ada hangs on to her leg, at Llanes' apartment in Havana, Cuba. She has forgiven them every transgression. It's hard to stay angry at a baby chimpanzee when it clambers up your leg and into your arms and plants a kiss on your cheek in a plea for forgiveness. (Photo by Ramon Espinosa/AP Photo)