The Arabian mare “Jenny” curiously sniffs at the child of Raphael Wöllstein, who is on his way to the train, on her daily walk through the Fechenheim district of Frankfurt, Germany on March 8, 2019. Her owner opens the stable door for the 22-year-old horse every morning. Then the animal can decide for itself where it wants to spend the day. So that nobody thinks she's escaped, a sign with the inscription “My name is Jenny, didn't run away, just go for a walk” is on the halter. (Photo by Boris Roessler/dpa)

Somali men carry swordfish from the sea to a market in the capital Mogadishu, Somalia Thursday, April 23, 2015. (Photo by Farah Abdi Warsameh/AP Photo)

A devotee dressed as Hindu Lord Shiva waits to participate in a parade during “Kumbh Mela” or the Pitcher Festival in Trimbakeshwar, India, August 18, 2015. The Kumbh Mela takes place four times every 12 years at four different river bank locations in India. (Photo by Danish Siddiqui/Reuters)

A team of ten acrobats form the shape of a racehorse crossing the winning post ridden by Stefanie Hofer to celebrate the upcoming Dubai Duty Free Shergar Cup at Ascot Racecourse on July 29, 2014 in Ascot, England. The Dubai Duty Free Shergar Cup is the only team-format raceday in the UK and takes place on 9th August. (Photo by Ian Gavan/Getty Images for Ascot Racecourse)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

People wearing bear furs perform during a festival of New Year ritual dances attended by hundreds in Comanesti, northern Romania, Wednesday, December 30 2015. In pre-Christian rural traditions, dancers wearing colored costumes or animal furs, toured from house to house in villages singing and dancing to ward off evil, in the present the tradition has moved to Romania's cities too, where dancers travel to perform the ritual for money. (Photo by Vadim Ghirda/AP Photo)

Ebiowei, 48, carries an empty oil container on his head to a place where it would be filled with refined fuel at an illegal refinery site near river Nun in Nigeria's oil state of Bayelsa November 27, 2012. Locals in the industry say workers can earn $50 to $60 a day. Thousands of people in Nigeria engage in a practice known locally as “oil bunkering” – hacking into pipelines to steal crude then refining it or selling it abroad. The practice, which leaves oil spewing from pipelines for miles around, managed to lift around a fifth of Nigeria's two million barrel a day production last year according to the finance ministry. (Photo by Akintunde Akinleye/Reuters)

A woman smokes marijuana during the annual 4/20 marijuana rally on Parliament Hill in Ottawa, Ontario, Canada, April 20, 2017. (Photo by Chris Wattie/Reuters)