A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)

An Indian nomadic shepherd from the western Rajasthan state guides his flock of sheep through an access road in Greater Noida, outskirts of New Delhi, India, Tuesday, December 5, 2017. Looking for suitable pasture lands for grazing, shepherds migrate their flocks over extensive areas in the same state or to neighboring states in India. (Photo by R.S. Iyer/AP Photo)

People walk past stranded cargo ship “Ocean Crown” during a windy weather in Klaipeda, Lithuania on December 26, 2017. (Photo by Ints Kalnins/Reuters)

A Hawaiian cleaner wrasse provides its cleaning services to a yellowfin goatfish in a reef community off the Big Island in Hawaii. Cleaner species help rid their hosts of ectoparasites, dead tissue, bacteria and fungi. Studies have shown cleaning to play a vital role in keeping many reef ecosystems healthy. (Photo by Marty Snyderman/Caters News Agency)

Enjoying a tickle from her keeper, an orphaned orangutan at the SOCP Quarantine Centre in Sumatra, Indonesia on March 20, 2016. The island’s orangutan population has been devastated in recent years as the forest areas are destroyed to make way for palm oil plantations. (Photo by Jami Tarris/Barcroft Media)

Pfc. Remy Bouchard swaps a cigarette for an egg with a French Orphan near La Haye Du Puits, France on July 18, 1944, which was captured by American forces. The boy is only twelve years old. (Photo by Hugh Broderick/AP Photo)

A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

Backdropped by a night time view of the Earth and the starry sky, the Space Shuttle Endeavour is seen docked to the International Space Station on May 28, 2011. (Photo by Reuters/NASA)