Students from St Andrews University are covered in foam as they take part in the traditional Raisin Weekend in the Lower College Lawn, at St Andrews in Scotland on October 22, 2018. The “raisin weekend” stems from a gift of raisins (now flour and foam) traditionally given by a first year student to their academic “parents” in gratitude for their guidance. (Photo by Russell Cheyne/Reuters)

A military cadet gets help from a colleague to adjust her hair before taking part the military parade in Bucharest, Romania, Saturday, December 1, 2018, as thousands turned out Saturday to celebrate 100-years since Romania became a modern-day state, amid concerns about rule of law and the state of democracy. Crowds braved temperatures of minus 5 Celsius (23 Fahrenheit) to watch the military parade of troops, tanks and military vehicles. (Photo by Vadim Ghirda/AP Photo)

People march past the Colosseum during the Gay Pride parade in Rome, Saturday, June 11, 2016. Italy joined the rest of Europe last month in giving some legal rights to gay couples after a years-long battle and opposition from the Catholic Church to anything that smacked of authorizing gay marriage. (Photo by Fabio Frustaci/AP Photo)

A visitor walks underneath a replica of a Titanosaur at the Cretaceous park in Cal Orcko, on the outskirts of Sucre, Bolivia, July 22, 2016. A footprint measuring over a meter wide that was made by a meat-eating predator some 80 million years ago has been discovered in Bolivia, one of the largest of its kind ever found. (Photo by David Mercado/Reuters)

Those lights are actually bioluminescent shrimp, better known as sea fireflies, or, in Japan, as “umibotaru”. Visible every year from May until the end of October, they live in the sand around very shallow sea water and are often seen floating between the extremes of high and low tides. Here: Bioluminescent sea fireflies glittering like diamonds on the rocks and sand. Okayama, Japan. July 2016. (Photo by Trevor Williams/Jonathan Galione/Getty Images)

Masked penitents holds their crosses during spring “Romeria Cruceros de Arce”, in Roncesvalles, northern Spain, Sunday, May 10, 2015. Every year on the second Sunday in spring, people with crosses march from their small Pyrenees towns to Roncesvalles Church in tribute of the Virgin. (Photo by Alvaro Barrientos/AP Photo)

In this photo taken April 15, 2015, Clay Hielscher of Overbrook, Kan., poses for a photo in his home made Iron Man suit. While he enjoys building the battlesuits of his favorite super hero, Hielscher said the real reason he is so passionate about his pastime is his 11-year-old daughter, Kyrianna. They design and construct the suits together. (Photo by Chris Neal/AP Photo/The Topeka Capital-Journal)

Elvis Presley tribute artist Bruce Stewart (L) of Georgian Bay, Ontario passes Lorenz Francke of Scarborough, Ontario during the four-day Collingwood Elvis Festival in Collingwood, Ontario July 25, 2015. Featuring over 120 Elvis tribute artists, it is the world's largest Elvis festival and last year hosted 30,000 visitors. (Photo by Chris Helgren/Reuters)