Josh Fischman, senior editor at Scientific American, discusses the potentially deadly effects of the bacteria that builds up around your bathtub, referred to as biofilm, which claims the lives of 99,000 people annually. Fischman notes that these biofilms are most harmful when they are found on medical devices like catheters, which are inserted into the body, and can cause illnesses like staph infections and pneumonia. Biofilm is naturally complicated because it is made of a matrix of bacteria that build on top of each other. Fischman digs into the ways in which scientists are attempting to fight biofilm and what that means for the treatment of other diseases as well.