Certified GKH Gardening Expert
Those are cicadas. You will not get rid of them, and they won't be treated. They remain in ground for most of their life, only coming out to shed its skin, grow wings, mate, and die. Some can still feed on trees, but most have no way of consuming food.
There are different waves that come in different numbers of years such as 7 years, 13, years, etc. Each is a different species.
They will not harm you or anything else, but they are VERY loud. standing under a tree filled with them for several hours can cause hearing damage. Any loud noises will also attract the to you, or the object making noise.
They are edible, however. The females are... the males are hollow, and quite useless for this purpose.