The blood has several types of white blood cells including neutrophils, bands, eosinophils, basophils, monocytes and lymphocytes. Each fights infection in a different way. Neutrophils, for example, are one of the body's main defenses against bacteria. Neutrophils kill bacteria by ingesting them. Neutrophils can ingest five to 20 bacteria in their lifetime. Another type of white blood cell is called bands. Bands are immature neutrophils.