Cicadas are insects belonging to the order Hemiptera and the family Cicadidae. They are known for their distinctive sound produced by males to attract females. There are over 3,000 species of cicadas worldwide, with varying life cycles, some emerging every year and others every 13 or 17 years, such as the periodical cicadas. Cicadas undergo a unique life cycle that includes several stages: egg, nymph, and adult. After hatching, nymphs live underground for several years, feeding on plant roots. Once they mature, they emerge, molt, and become adults, often characterized by their large eyes and transparent wings.