We have them every year in August. There must be different varieties. I dread having more than the yearly ones out.
There are different varieties. The annual cicadas emerge in late summer, in areas that have them. They're larger than the long-period cicadas, and have green eyes. The long-period cicadas (7 year, 13, year, 17 year, whatever) have red eyes and are usually far more numerous than the annual variety.