Evidence of cicadas spotted across parts of DC region as insects begin to emerge

ARLINGTON, Va. - They're back! Evidence of the cicadas – the red-eyed insects that emerge from underground every 17 years – are being spotted across parts of the D.C. region!

FOX 5's Bob Barnard was in the Arlington area Tuesday where he found brown shells clinging to trees and open holes in the ground -- telltale signs that the bugs are here.

BROOD X: MYTH THAT CICADAS INCREASE COPPERHEAD SIGHTINGS DEBUNKED

Cicada sightings are not widespread just yet. But as the temperatures continue to warm more of them will emerge any day now and experts say we can expect billions of the insects across the East Coast.

CICADAS 2021: BROOD X STARTING TO EMERGE FOR THE FIRST TIME IN 17 YEARS

Here's what we know about the cicadas:

- They are a family of insects called magicicadas.

- This year's group is called Brood X.

- Brood X can be seen in Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and Washington, D.C.

- Why so many? An evolutionary defense mechanism! Large numbers mean lots of survivors.

- The noise the male cicadas make is a mating call.

- Once the males mate, they die. After females lay their eggs, they die. So except for the eggs, they'll be gone by around July 4.

- After Brood X -- two different broods will come out in 2024.

- They're not dangerous to people or pets – although some dogs have been known to eat too many!

- They can harm young trees as they try to plant eggs on weak limbs. Netting the trees can help.

- When the die they fertilize the trees -- and may smell a bit!