The Olympics fever has gone viral around the world. People are rooting for their countries and praising athletes for bringing home gold, silver or bronze medals. While several medals are being awarded to various Olympians across different sports, have you ever stopped to wonder why these athletes bite on their medals during their victory pose?

Well, you are not the only one in quest of the "medal-biting" habit. From Jamaica's Usain Bolt to GBR's Mo Farah, all the winning Olympians in this year's Rio 2016 Olympics have posed biting on their gold medals. Any medal, be it gold, silver or bronze, is definitely not edible and the main reason behind this unconventional habit is simply to please the photojournalists.

It is not a trend that has picked up recently, but has been followed by athletes for years now.

"It's become an obsession with the photographers," David Wallechinsky, president of the International Society of Olympic Historians and co-author of "The Complete Book of the Olympics," told CNN in 2012. "I think they look at it as an iconic shot, as something that you can probably sell. I don't think it's something the athletes would probably do on their own."

But it is also a common practice to test the authenticity of gold. But the Olympians are already aware of the fact that the gold medals they've won aren't really made of gold, but have fragments of the precious medal. The Olympic gold medals weigh 500 grams each. They contain about 1.34 percent of gold and rest of it is sterling silver.

The last Olympic gold medals made of solid gold were in the Stockholm Games of 1912, but after the World War II, which caused shortages in the precious metal, medals were made of mixed silver.

According to Anthony DeMarco of the Forbes Magazine, today's medals are "the most sustainable ever made." As for the silver medals, DeMarco told ABC News that it is "30 percent recycled, using mirrors, X-ray plates and other kinds of refuse." DeMarco said that the cost of each Olympic medal is about $564, which is way less than the winnings they get besides the medallions.

For instance, in the U.S., gold winners are awarded $25,000, which is taxed by the government as income earned abroad; Kazakhstan gives each of its gold medallists $250,000 and Malaysia actually gives its winners a bar of solid gold.

Clearly, the Olympians biting on their medals are simply posing for a great photograph.