Wired consulted with entomologist Dr. Samuel Ramsey to learn more about why and how cicadas are so loud when they come to the surface. Dr. Sammy explained that the male cicada has a unique organ called a tymbal within his abdomen that vibrates and then echoes off the ribs, making the distinct humming sound for which the insects are known. The females will respond with clicking noises to attract the male of their choice. Additionally, the noise is used to warn predators that the cicadas are in great multitudes and to stay away.
Dr. Sammy explains why it’s so important for cicadas to gather in large groups and make lots of noise.