You may have heard that dollar bills harbor trace amounts of drugs.
But those greenbacks in your wallet are hiding far more than cocaine and the flu. They're teeming with life.
Each dollar bill carries about 3,000 types of bacteria on its surface, scientists have found. Most are harmless. But cash also has DNA from drug-resistant microbes. And your wad of dough may even have a smudge of anthrax and diphtheria.
In other words, your wallet is a portable petri dish.