CHICAGO (WGN) — Cicadas are now past their peak in many areas and will soon be gone for good.

Many locations across the U.S. that were flooded with cicadas for weeks are starting to notice a lack of activity.

The ground had seemed to undulate at night, alive with bugs. Crawling cicada nymphs, striving to get higher after 17 years underground, marched en masse toward and up trees, pausing to shed their skin and emerge as adults.

Trillions of once-hidden baby bugs were in the air, on the trees and perching upon people’s shirts, hats and even faces. They were red-eyed, loud and frisky.

The big question now is: What should you do with all of the cicada carcasses and exoskeletons left behind?

According to the Morton Arboretum, you should put them to good use. The arboretum suggests scooping up the carcasses and shells and scattering them in areas you want plants to grow. They make great fertilizer.

Also, for anyone experiencing a stench due to the cicada carcasses, the arboretum recommends using a lawnmower to clear them from your yard. They say it will help take the odor away faster.

Marvin Lo, a tree root biologist at the Morton Arboretum, said overall, cicadas play an important role in the local ecosystem as fertilizer, aerating the soil and food for birds and other animals.

The Associated Press contributed to this report.