How many cicadas stay underground for 13?

Certain species of cicadas, particularly the periodical cicadas, spend 13 years underground as nymphs before emerging as adults. This life cycle is characteristic of the 13-year cicadas, which belong to the genus Magicicada. There are four species within this group, each synchronized to emerge in specific years, resulting in massive swarms. Their unique life cycle is an adaptation to avoid predation and ensure survival.