A rare double emergence of periodical cicadas is projected across the American Midwest and South this summer.

The event marks the first simultaneous appearance of these broods since 1803, offering unique research opportunities.

Trillions of cicadas, representing all seven species, will provide data for studies on evolution, behavior, and climate impact.

The emergence will benefit the environment by aerating the soil and serving as a food source for wildlife.

Researchers will investigate the effects of a parasitic fungus during the co-emergence in Illinois.

While the cicadas' vast numbers will create a noticeable chorus, they pose no significant threat to humans, pets, or the environment.