A dog groomer prepares a model dog during the 2nd Annual Shenzhen International Pet Exhibition, July 14, 2016, in Shenzhen, China. The pet exhibition runs from July 14 - 17, 2016 at the Shenzhen Convention & Exhibition Center. (Photo by VCG/Getty Images)

Supporters of former Democratic presidential candidate Bernie Sanders hold up posters at a “Black Men For Bernie” rally to gain support for third party candidates and protest the DNC during the 2016 Democratic National Convention on July 27, 2016 in Philadelphia, Pennsylvania. (Photo by Patrick T. Fallon/AFP Photo)

Nuns from the United States dance as they wait for the Holy Mass with Pope Francis (not seen) at the Campus Misericordiae in Brzegi, Poland, 31 July 2016. Today Pope Francis will celebrate the holy mass ending the World Youth Day 2016 in Poland. (Photo by Marcin Obara/EPA)

Ukrainian teenagers hit each other with pillows during a large pillow fight in downtown Kiev, Ukraine, 24 April 2016. About hundred people took part in the event “Pillow battle 2016” in Kiev. (Photo by Roman Pilipey/EPA)

A fly rides a butterly, July 2016. (Photo by Petar Sabol Sharpeye/Rex Features/Shutterstock)

A man pushes her daughter on a cart as they shop at a market in Seoul, South Korea, July 26, 2016. (Photo by Kim Hong-Ji/Reuters)

Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)

A boat is stranded on Poyang Lake in Lushan City, China during low-water season on November 3, 2016. (Photo by Xinhua/Barcroft Images)