A tribal Fulani man milks a cow at a local milk collecting centre in Dangwala Karfi village on the outskirts of Nigeria's northern city of Kano January 19, 2016. (Photo by Akintunde Akinleye/Reuters)

In this December 13, 2014 photo, Ricardo Alegria holds his donkeys by a leash as he yells to sell their milk in the streets of Santiago, Chile. Alegria, along with his brother Marco, has been selling fresh donkey milk for the past 25 years, and says it's recommended as a vitamin boost. Shot glass size cups of the drink sell for about $2 dollars. Half a liter, which is the most he says his donkeys can give in one day, sells for about $20 dollars. (Photo by Luis Hidalgo/AP Photo)

Devotees push the chariot of Rato Machhindranath during the chariot festival at Bungamati in Lalitpur April 22, 2015. Rato Machhindranath is known as the god of rain and both Hindus and Buddhists worship Machhindranath for good rain to prevent drought during the rice harvest season. (Photo by Navesh Chitrakar/Reuters)

A Nepalese devotee prepares for a religious mask performance during the Seekaali Festival in Khokna village, near Kathmandu, Nepal, 07 October 2016. During the 300-year-old Seekali festival, elderly ethnic Newari devotees wear masks of 14 various goddesses including Lord Ganesha, Lord Shiva, Lord Laxmi, Lord Brahma and Lord Bishnu. The Khokna people celebrate the Seekaali festival as an alternative of the Dashain festival which is biggest festival of Nepalese Hindus that celebrates the victory of the gods over demons. (Photo by Narendra Shrestha/EPA)

Rebel fighters from the Jaish al- Fatah (or Army of Conquest) brigades manoeuver an alleged explosive- rigged make- shift armoured vehicle during a major assault on Syrian government forces West of Aleppo city on October 28, 2016 Syrian opposition fighters launched a major assault on government forces to break a months- long siege of rebel- held neighbourhoods of the battered city of Aleppo. Rebel groups including the powerful Ahrar al- Sham faction and former Al- Qaeda affiliate Fateh al- Sham Front fired waves of rockets into government- held western Aleppo, killing at least 15 civilians, a monitor said. (Photo by Omar Haj Kadour/AFP Photo)

In this Monday, June 20, 2016 photo, a Palestinian girl plays in a barrel as her mother bakes bread for a Ramadan dinner at their house in el-Zohor slum, on the outskirts of Khan Younis refugee camp, southern Gaza Strip. (Photo by Khalil Hamra/AP Photo)

Commuters use a plastic sheet to take shelter from rain as they ride through a waterlogged road in Ahmedabad, India, July 27, 2016. (Photo by Amit Dave/Reuters)

People hold umbrellas as they walk past a flooded street in Taiyuan, Shanxi Province, China, July 19, 2016. (Photo by Reuters/China Daily)