Did you know cicadas are as loud as opera singers?
An African cicada species* was recorded at almost 107 decibels when measured at 50 cm. That’s almost as loud as loud as a live rock concert (114 dB) or Smilyana Zaharieva, the world’s loudest opera singer (113 dB) . Cicada songs are used to help them communicate with each other, find mates, and possibly also drive away potential predators .
There are about 3000 species of cicadas. Two species synchronize their development to hatch as flying adults at the same time for 13 or 17 years, only to mate and die within a couple weeks . A possible explanation is that they evolved to only emerge as adults at prime number yearly intervals to avoid predation by species which can’t synchronize with 13- or 17-year intervals . So, one could even argue that cicadas are not just just the world’s loudest insects, they also invented prime numbers!
* Brevisana brevis
 Guiness World Record - Loudest mezzo soprano vocal note