According to the CDC, N. fowleri normally eats bacteria. But when the amoeba gets into humans, it uses the brain as a food source. The nose is the pathway of the amoeba, so infection occurs most often from diving, water skiing, or performing water sports in which water is forced into the nose. But infections have occurred in people who dunked their heads in hot springs or who cleaned their nostrils with neti pots filled with untreated tap water.