These photographs of hundreds of ducks following their leader down a river are truly mesmerizing. Rafeur Rahman of Bangladesh climbed a high bridge and saw hundreds of ducks apparently playing a game of follow the leader. More than 500 ducks live on the river, where the mosses and snails provide the perfect habitat. Here: Ducks in the river Baral in Bangladesh. (Photo by Rafeur Rahman/Caters News Agency)

Muhannad al-Kadiri (R),18, and Ibrahim Eid, 16, demonstrate their Parkour skills over a military vehicle in the rebel-held city of Inkhil, west of Deraa, Syria, February 4, 2017. (Photo by Alaa Al-Faqir/Reuters)

Players perform during a game at the first Bubble Soccer tournament in Hitzkirch, near Lucerne, Switzerland, June 27, 2015. Bubble Soccer, also known as Zorb Soccer, is becoming increasingly popular around the world. The game is a recreation of playing soccer whilst encased in an inflated zorb which covers the players upper-body and head. (Photo by Urs Flueeler/EPA)

A traffic police woman whistles at a pedestrian, Monday, July 27, 2015, in Pyongyang, North Korea where its citizens are having a one-day national holiday to celebrate the country's 62nd anniversary of the armistice that ended the Korean War. (Photo by Wong Maye-E/AP Photo)

“Sunward”. When the Mediterrenean Mantis opened its wings, It seemed very impressive at the sunshine... Photo location: Nicosia, Cyprus. (Photo and caption by Hasan Baglar/National Geographic Photo Contest)

A pro-Russian supporter with the Russian national flag on her shoulders takes part in a meeting in Simferopol, March 6, 2014. Crimea's parliament voted to join Russia on Thursday and its Moscow-backed government set a referendum within 10 days on the decision in a dramatic escalation of the crisis over the Ukrainian Black Sea peninsula. (Photo by Vasily Fedosenko/Reuters)

“Basunga”. Basunga (3 weeks-old newborn with albinism) is happily sleeping with his cousin. For now, he does not yet realize the difficulties he will face to integrate into the Congolese society as a PWA. The success of his integration will greatly depends of how he accepts himself and his skin condition a and how educated he will be. Photo location: Kinshasa, Congo RDC. (Photo and caption by Patricia Willocq/National Geographic Photo Contest)

An American soldier walks ahead of an MKIV (Mark IV) British-made tank, circa 1918. (Photo by Hulton Archive/Getty Images)