How do 17-year cicadas, which live underground as nymphs, track the passage of time so they all emerge synchronously as adults?
Magicicada septendecula male (Brood IX). (Credit: C. Simon / doi:10.1371/journal.pone.0000892)

How do 17-year cicadas, which live underground as nymphs, track the passage of time so they all emerge synchronously as adults?
Magicicada septendecula male (Brood IX). (Credit: C. Simon / doi:10.1371/journal.pone.0000892)