Cicadas are known for their loud and distinctive mating calls, which can be quite noisy during their annual emergence. The reason behind their noise is directly related to their reproduction and mating behavior.
Male cicadas produce the noise by scraping their wings against a file on their abdomens. This structure, called a “tymbal,” acts like a tuning fork, and when the wings are rapidly vibrated, it produces a clicking or buzzing sound. The faster the wings are vibrated, the higher the pitch of the sound.The structure of the cicada’s body also contributes to the volume of their calls. The exoskeleton acts as a natural amplifier, much like the body of a guitar or violin, turning the relatively small movements of the tymbals into a loud, piercing sound that can carry over long distances.
The primary purpose of this noise is to attract females. Female cicadas are attracted to the sound of male cicadas and use it to locate potential mates. The males, in turn, compete with each other to produce the loudest and most persistent calls to ensure they are noticed by the females. This behavior is a form of sexual selection, where the loudest calls can be seen as a sign of good health and genetic fitness.
Additionally, the noise made by cicadas can also serve as a deterrent to predators. Some predators may find the sound unpleasant or even overwhelming, and this can prevent them from approaching the cicadas, thus providing a level of protection.
Cicadas are not actively trying to be noisy or bother humans; their calls are an essential part of their life cycle and reproductive strategy. The noise is a direct result of their biological mechanisms for reproduction and is not intended as a nuisance to other species, including humans.