h they gently suck the juices. Nourished by this root sap, they begin to grow. They shed their skin four times before they reach adult size.
             Once matured, a cicada does not necessarily leave its underground nursery. All cicadas of the same generation in a region wait for a seventeenth spring before they come creeping forth from the ground as a group. The eeriness of this group effort has puzzled humans for centuries. People have responded to the mystery with a host of superstitions, educated guesses, and scientific theories.
             One of the earliest explanations for the mass appearance of cicada populations after their long absence in an area was that the insects had come to foretell war. This idea stems from an observation of the adult cicada shortly after it appears above ground. It immediately sheds its skin for the last time and begins to darken in color. Near the outer edge of its front wings, a black mark appears that looks distinctly like the letter W. Some thought this W stood for "war." In the past,
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