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)

Afghan dogs fight during the weekly dog fight in Kabul, Afghanistan, 17 February 2017. Under the Taliban dog fighting was forbidden, but since their fall it has become a major source of entertainment for hundreds of Afghans, where bets can amount to thousands of dollars and the dogs, which must be over one year old, are well-cared for by their owners and fed milk, butter and meat. (Photo by Hedayatullah Amid/EPA)

People run in panic after a coalition airstrike hit Islamic State fighters positions in Tahrir neighbourhood of Mosul, Iraq, November 17, 2016. (Photo by Goran Tomasevic/Reuters)

Jazmin, 6, sister of Jose Luis, receives Isoniazid Preventive Therapy in Carabayllo in Lima, Peru July 14, 2016. At least 30,000 Peruvians are infected with tuberculosis, an ancient disease that killed 1.8 million globally last year, more than AIDS-related and malaria deaths combined. Partners in Health, a Boston-based non-profit that works with Peru's health ministry, offers a simple solution. It trains community volunteers to tend to tuberculosis sufferers in their homes – ensuring patients take medicine daily and helping them navigate the public health bureaucracy. (Photo by Mariana Bazo/Reuters)

Warriors from the Suri tribe in Ethiopia still stage the savage “Donga” battles – even after many fighters have been died from their injuries. Donga stick fights take place after the harvests, the Surmas count days owing to knots on a long stem of grass or jags on the trunk of a tree dedicated to that specific use. Here: A tribeswoman sporting a huge lip plate and wearing a skinned animal carcass on her head. (Photo by Eric Lafforgue/Exclusivepix Media)

French bulldog Watson is wheeled to a ring for judging at the 2016 Westminster Kennel Club Dog Show in the Manhattan borough of New York City, February 15, 2016. (Photo by Mike Segar/Reuters)

Puppies, pugs and the perfect antidote to political pandemonium, it’s the Kennel Club’s dog photographer of the year competition. Here: Jamie Morgan’s two Afghan hounds won first place in the portrait category. (Photo by Jamie Morgan/PA Wire)

Shrine Parishioners pull their portable shrine during Nada No Kenka Matsuri, or Nada Fight Festival at Matsubara Hachiman Shrine on October 16, 2011 in Himeji, Hyogo, Japan. The fight, the highlight of the shrine's Autumn Harvest Festival, attracts 100,000 people. (Photo by Buddhika Weerasinghe/Getty Images)