During thier time searching for a mate, members of this insect family commonly feed on plant sap, congregating on the leaves and trunks of trees, and using a strong needle like mouth-piece to pierce the tough outer layer of the plant. Due to the large amount of sap some species can consume there has been reports of plant growth being affected. Despite this mouth piece, cicada don't bite, however thier claws are prickly to the touch and stronger than expected.
The sound of cicadas are well known, thier familiar chirp being commonplace in the warmer months accross Australia, however it is interesting to note that some species have a call/chirp as loud as a chainsaw or thunderclap, measuring at 120 decibels. Yep you read that right an insect has the noise capacity to force you to wear ear-plugs because it is physically painful, while this isnt commonplace it really places into perspective how much we underestimate a family of insects we often over look.
Next time you go for a bush walk or hike, take a moment to stop and listen to the summer chirps of native cicadas, and marvel at the fact that those songs were years in the making.