There is still much mystery surrounding the Brood X cicadas

The eastern half of the U.S. is about to experience a rare, mysterious event that is still confusing scientists.

The Brood X cicadas are getting ready to emerge. They are said to have one of the most interesting lifestyles of any creature on Earth.

They have been underground for the last seventeen years feeding on tree sap in roots. When they emerge, they will mate in the trees and the offspring will then burrow into the ground to live for another seventeen years before coming out again.

One entomologist says that there are still mysteries surrounding the species.

“How does that insect-- that live underground with no opportunity to view visible light-- how are they counting those seventeen years underground? Is it an internal molecular clock? We don’t know precisely what cues the cicadas use to trigger that massive emergence,” Michael Raupp with the University of Maryland explains.

This is not the only rare breed, another group appears every thirteen years. These moments are one of the few chances scientists get to study the noisy creatures.