Miniature pig “Nueffel” is walked in a park in Hanover, Germany, 14 April 2016. (Photo by Sebastian Gollnow/EPA)

A participant runs in high-heels as she competes in the Stiletto Run in Bucharest June 14, 2014. The annual 50 metres race requires participants to wear high-heels that are at least 7cm tall. (Photo by Bogdan Cristel/Reuters)

“Kilauea Rules”. The most extreme place we put ours kayakers to paddle till now. Photo location: Big Island, Hawaii. (Photo and caption by Alexandre Socci/National Geographic Photo Contest)

A pangolin carries its baby at a Bali zoo, Indonesia, Thursday, June 19, 2014. The pangolin baby was born on May 31. (Photo by Firdia Lisnawati/AP Photo)

Women wearing sunglasses pose for a group photo at a park in Beijing in 1980. (Photo by Reuters/China Daily)

Children play football in front of an abandoned train compartment next to a railway track in Dhaka, in this May 29, 2014 file photo. (Photo by Andrew Biraj/Reuters)

This photo provided by Netflix/naturepl.com and WWF-International shows an African Elephant (Loxodonta africana) in front of double rainbow, in Masai Mara, Kenya, included in the Netflix natural history series, “Our Planet”, in collaboration with Silverback Films and WWF. The eight-part series debuts in 2019. (Photo by Andy Rouse/Naturepl/WWF-International/Netflix via AP Photo)

Pupils of the Dao ethnic tribe return home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)