They can reproduce every 20 minutes. The number of bacteria on your body right now is greater than the number of people in the United States. Like people, bacteria may be good or bad, depending on what they do to you or for you. And like people, bacteria are here to stay. We can't get rid of them, so we must learn to live with them.
Some bacteria spend their lives in the small folds of the skin, on hair or under fingernails.
Others cause body odor. Still others, called pathogens, cause disease. They exist on the skin of normal, healthy people, and are usually not harmful. They're always there and can't be removed completely. Other bacteria are transferred to your skin in one way or another.