A three-month-old Sumatran tiger cub named “Bandar” shows his displeasure after being dunked in the tiger exhibit moat for a swim reliability test at the National Zoo in Washington, on November 6, 2013. All cubs born at the zoo must take a swim test before being allowed to roam in the exhibit. Bandar passed his test. (Photo by Manuel Balce Ceneta/Associated Press)

Gorillas at Royal Burgers’ Zoo, Arnhem, Netherlands, on November 28, 2013. (Photo by Vidi Photo/Startraks Photo New York)

A picturesque supercell formation in the northwest of Booker, Texas from June 2013. (Photo by Mike Olbinski/Barcroft Media)

A man is silhouetted as he stands on a walkway in the sky lobby at the Chancellery, the seat of German Chancellor Angela Merkel (not pictured) in Berlin, May 7, 2014. (Photo by Thomas Peter/Reuters)

A crew members walks on the flight deck past Super Etendard fighter jets aboard France's Charles de Gaulle aircraft carrier on missino in the Gulf, January 29, 2016. (Photo by Philippe Wojazer/Reuters)

Characters dressed as Elmo and Cookie Monster who pose for tips take a photo by request from a tourist (2nd R, black pants) in Times Square in the Manhattan borough of New York City, January 29, 2016. (Photo by Rickey Rogers/Reuters)

Children play in front of a brick factory on the outskirts of the northern Myanmar city of Mandalay on December 14, 2015. (Photo by Phyo Hein Kyaw/AFP Photo)

Pornstar Asa Akira made an appearance at the new Pornhub shop in New York, USA on Friday, November 25, 2017. Pornhub is a pornographic video sharing website and the largest pоrnography site on the Internet. The new pop-up will be open in New York's SoHo until 20 December. (Photo by Curtis Means/ACE Pictures/Rex Features/Shutterstock)