How does a cicada live underground for 17 years??
Cicadas stay underground as nymphs, and go to the surface when they reach maturity. Cicadas must emerge from underground just before becoming adults so, as adults, they can fly and find a mate. It takes them 17 years to mature from nymph to adult (somewhat like us and our 12 years to puberty). Thus, their life cycle mainly determines when they crawl out. Also the temperature must exceed about 64°F (18°C). By the way, the nymphs don’t hibernate while underground. They do experience 4 years of slow growth (not real hibernation). After that, 17-year cicadas grow at the same rate as the 13-year cicadas. They spend their subterranean life eating and growing. The stubby nymphs look much like adults without wings and have six powerful legs, some modified for digging.
