Sugar gliders, Candy and Popcorn, enjoy their favourite food, Nectar, at Wild Life Sydney Zoo on February 14, 2017 in Sydney, Australia. The treat made up of honey, high protein baby cereal and egg yolks is the human equivalent to chocolate to the Sugar Gliders. St. Valentine's Day or the Feast of Saint Valentine began as a celebration of the early Christian Saint Valentinus. From the 18th Century onwards it has steadily transformed into a celebration of romantic love and sentiment in many countries around the world. (Photo by James D. Morgan/Getty Images)

A deer forages for food in the early morning sun as cooler temperatures bring on the autumn season at Dunham Massey on on October 11, 2010 in Lymm, England. Shortening daylight hours and cooler weather brings on the rutting season for Red and Fallow deer herds and Autumn foliage colours across Britain. (Photo by Christopher Furlong/Getty Images)

“Eye of a toad”. Animal Portraits, Łukasz Bożycki, Poland. Early spring sees a pond near Łukasz’s home city of Warsaw, Poland, full of mating frogs and a few toads. On this March day, Łukasz shared the pond with them for an evening, sitting in the icy water in his chest-high waders, keeping as still as possible, despite the numbing cold, so that the amphibians could get used to him. “I wanted to find a fresh way of portraying the amphibians”, he says, “at water level”. Using a telephoto lens, he focused on one lone toad and waited for the sun to dip almost below the horizon before pressing the shutter, using flash to bring out the details in the shadow. His prize was “the glorious pool of sunset colour” and fiery glow of the toad’s eye. Nikon D80 + 70-300mm f4.5-5.6 lens + extension tube; 1/125 sec at f9 (-2.3 e/v); ISO 100; built-in flash. (Photo by Łukasz Bożycki)

A Chimpanzee is seen with funny expressions at Hanover Zoo on September 27, 2013 in Hanover, Germany. (Photo by Barcroft Media)

Shortlisted: “Two big eyes” by Miao Yong (Zejiang province, China). Damselflies look over the leaves. “I was photographing insects in a park near my home when suddenly I found two damselflies in the grass. They kept flying and it was very difficult to focus until suddenly they parked behind a leaf”. (Photo by Miao Yong/2017 Royal Society of Biology Photographer of the Year)

Sun Model students pose for a photo during a training session at the school on March 31, 2014 in Phnom Penh, Cambodia. Having started in August 2010 with only three models, the Sun Model Agency and School is starting to make an impact in the fashion industry in Cambodia. (Photo by Omar Havana/Getty Images)

A baby otter has its first health checkup at Chester zoo, England on May 2, 2018. It was among five pups being weighed and microchipped. (Photo by Peter Byrne/PA Wire)

A monkey jumps from a branch at Yangon Zoological Gardens in Yangon, Myanmar, 06 April 2016. Yangon Zoological Gardens (Yangon Zoo) is the oldest and second largest zoo in Myanmar. (Photo by Lynn Bo Bo/EPA)