Tropical acrobatics by Adrià López Baucells in Manaus, Brazil. An unidentified South American marsupial, although the characteristic black markings on its face indicate it may be a mouse opossum. These small creatures are nocturnal and feed on bugs, fruit and bird eggs. (Photo by Adrià López Baucells/2019 Royal Society of Biology Photography Competition)

A hyena kisses his own reflection while appearing to walk on water. (Photo by Jake De Wet/Caters News Agency)

A woman takes a photo on her mobile phone of a tiger during the media preview of Vivid Sydney at Taronga Zoo on May 19, 2019 in Sydney, Australia. An illuminated trail of almost 300 lit lanterns of endangered species will glow every night at the zoo during Vivid Sydney which runs from May 24 throughout Sydney with hundreds of lit buildings and exhibits which attract hundreds of thousands of visitors each year. (Photo by James D. Morgan/Getty Images)

Indian Air Force soldiers toss their rifles as they perform during the full-dress rehearsal for Indian Air Force Day at the Hindon air force station on the outskirts of New Delhi October 6, 2015. (Photo by Anindito Mukherjee/Reuters)

Sculptures entitled “The Rising Tide” by British sculptor Jason deCaires Taylor are seen beside the River Thames in front of the Houses of Parliament and the London Eye ferris wheel in London, September 3, 2015. The representations of four horses and riders are fully visible at low tide but become immersed underwater twice a day as the Thames rises to reach full tide. The installation will be on display throughout September as part of the annual Totally Thames festival. (Photo by Toby Melville/Reuters)

Lazar and his sister Andjelka sit by a candle in their home in the eastern Serbian town of Majdanpek, December 4, 2014. Electricity workers in Serbia struggled through snow, ice and treacherous terrain on Thursday to restore electricity to an eastern town left shivering without power, heating or running water for a fourth day. (Photo by Marko Djurica/Reuters)

In this April 2, 2015 photo, dog owner Laura Aquilina strolls with her two year old Rottweiler Brutus, who was recently fitted with prosthetics on all four paws, and is currently learning to use them, near Aquilina's home in Loveland, Colo. Brutus lost all four paws to frostbite as a puppy while under care of a breeder, and Aquilina began caring for him about a year ago. (Photo by Brennan Linsley/AP Photo)

An Israeli boy swims next to sheep belonging to a Palestinian farmer in the West Bank village of Al-Auja in the Jordan Valley on April 8, 2015 during the Jewish Passover holiday. Thousands of Israelis spent the day outdoors, picnicking and touring the country during the eight-day Passover holiday, which commemorates the Israelites' exodus from Egypt some 3,500 years ago. (Photo by Menahem Kahana/AFP Photo)