Four-month-old fox cubs squaring up to each other in Walthamstow, England on August 7, 2015. (Photo by Greg Morgan/Barcroft Media)

Attendees at Wizard World Comic Con walk through hallways in Chicago, Illinois, United States, August 22, 2015. (Photo by Jim Young/Reuters)

A participant smiles at the annual Christopher Street Day parade on Kurfuerstendamm in Berlin, Germany, June 27, 2015. (Photo by Fabrizio Bensch/Reuters)

A man rows a boat on the Dal Lake as a woman holds an umbrella during snowfall in Srinagar February 19, 2015. (Photo by Danish Ismail/Reuters)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

Ukrainian Air Force officers attend a graduation ceremony at the National University of Defence of Ukraine in Kiev, April 24, 2015. (Photo by Gleb Garanich/Reuters)

Model Yasmine Petty arrives on the Life Ball plane on May 15, 2015 in Vienna, Austria. The Life Ball, an annual charity ball raising funds for HIV & AIDS projects, will take place on May 16, 2015 at the city hall in Vienna. (Photo by Monika Fellner/Getty Images)

A picture made available on 08 July 2015 showsa lightning strikes during a heavy storm over Poznan in the night of 07 July 2015. Severe storms passed last night over Poland causing lots of damages to buildings, trees, electricity and railway tractions. (Photo by Lukasz Ogrodowczyk/EPA)