Discover a process called quorum sensing, which enables bacteria to detect other bacteria of the same species in their surrounding environment in this video segment adapted from NOVA scienceNOW. With enough bacteria present, they can undertake a group activity, such as producing a luminescent glow or spreading disease. Professor Bonnie Bassler and her team of researchers recently discovered that certain bacteria communicate not only to their own species but to other species around them. This work may help pave the way to new drug treatments that combat bacterial diseases.