The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

DJI Phantom 3 Severe Crash - Train Bridge

Cool rider Ace on the back on the motorbike, on January 12, 2015, in Surabaya, Indonesia. A pair of dogs enjoy a bit of bark-and-ride – as they weave through Indonesiaís traffic on the back of a motorcycle. Wearing red-framed sunglasses and a helmet the two golden retrievers happily sandwich their owner on the fast bike. Unsurprisingly, the sight of the docile dogs hitching a fast ride in Surabaya, Indonesia, attracts a lot of attention from onlookers. Ace and Armani have been riding since they were just a few months old and now at the age of three the pair jump onto the bike whenever they think their owner is heading out. (Photo by Jefta Images/Barcroft Media/ABACAPress)

A Western Lowland Gorilla baby named “Mjukuu”, that was born in October last year, rides on the back of its Mother “Mbeli” in their enclosure at Taronga Zoo in Sydney, Australia, May 19, 2015. The baby gorilla was born six days ago, and is the second sired by the zoo's new Silverback, Kibali, who arrived from France in 2012. (Photo by David Gray/Reuters)

A heat-stressed koala waits as a resident pours water on its back on December 19, 2015 in Adelaide, Australia. Adelaide is experiencing an extreme heatwave, with temperatures reaching over 40 degrees for five consecutive days. (Photo by Morne de Klerk/Getty Images)