Have you seen any cicadas yet?

If you live in Tennessee, you may soon spot one of the noisy insects, if you haven't already. The Volunteer State is one of 17 states around the Southeast and Midwest that is welcoming trillions of cicadas in a rare, double brood event.

Tennessee will see cicadas from Brood XIX, which emerges every 13 years and will be found in more states than the 17-year Brood XIII, although both are expected to emerge in parts of Illinois and Iowa.

These periodical cicadas have been underground for over a decade, waiting for the right conditions to emerge, feed, mate and die, when the next generation will then head underground to start the cycle all over again.

Watchful eyes have already spotted Brood XIX cicadas above ground in parts of Tennessee, and more are likely on the way soon. Here's what you should know.

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When are cicadas expected to emerge in Tennessee?

According to Cicada Mania, the insects begin to emerge when the soil 8 inches underground reaches 64 degrees, and are often triggered by a warm rain.

Emergence dates may vary around the country, but Brood XIX has already been spotted in Tennessee and across the Southeast and is expected to emerge more broadly around the eastern U.S. by mid-May.

Which cicada brood is in Tennessee?

Tennessee will only see one of the two broods emerging this year: Brood XIX. The brood last emerged in 2011, and after this year, is set to emerge again in 2037.

Besides Tennessee, Brood XIX will also be found this year in the following states: Alabama, Arkansas, Georgia, Illinois, Iowa, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma and South Carolina.

Where have cicadas been reported in Tennessee?

Brood XIX cicadas have already been spotted a few places in Tennessee, according to Cicada Safari, a cicada tracking app by Mount St. Joseph University in Cincinnati, Ohio.

Cicada Safari users have spotted cicadas in the state around the Nashville area, near Murfreesboro, Columbia and Kingston Springs. They have also been spotted in northwest Tennessee, east of Clarksville, and in southeastern Tennessee, north of Chattanooga.

The Cicada Safari app allows users to submit pictures and video of cicadas in their area, which builds an interactive map tracking the species as they emerge this year.

So far, Cicada Safari users have seen Brood XIX in states including Georgia, North Carolina, South Carolina, Alabama, Mississippi, Tennessee, Arkansas, Kentucky and Missouri.

2024 cicada map: Check out where Broods XIII, XIX projected to emerge

The two cicada broods will emerge in a combined 17 states across the Southeast and Midwest, with two states − Illinois and Iowa − hosting both broods.

What's so special about the two broods coming out at the same time?

Trillions of Brood XIX and Brood XIII periodical cicadas will emerge this year, which they will stay above ground for a few weeks, where they will eat, mate and die, and new offspring will move underground to wait for another 13 or 17 years.

While both annual and periodical cicadas come out in various areas every year, it is rare for two different broods to emerge at the same time.

Brood XIII (13) has a 17-year life cycle, and last emerged in 2007. Like the other brood, they will begin to emerge in their area once the soil 8 inches underground reaches 64 degrees, and are also often triggered by a warm rain. They will be found in Indiana, Illinois, Iowa, Michigan and Wisconsin.

Broods XIX and XIII last emerged together 221 years ago in 1803, when Thomas Jefferson was president and there were only 17 states in the Union. After this year, they are not expected to emerge again at the same time until 2245.

Send your cicada photos to The Tennessean!

Email your photos to trending reporter and digital producer Joyce Orlando at [email protected] for them to appear in a future cicada story or gallery on The Tennessean, part of the USA TODAY Network.