Humans are Herbivores.
The creatures are all-natural and their existence does not contribute to the degradation of the planet.
https://www.cicadamania.com/TL;DR
"Once the cicada hatches from the egg it will begin to feed on the tree fluids. At this point, it looks like a termite or small white ant. Once the young cicada is ready, it crawls from the groove and falls to the ground where it will dig until it finds roots to feed on. It will typically start with smaller grass roots and work its way up to the roots of its host tree. The cicada will stay underground from 2 to 17 years depending on the species. Cicadas are active underground, tunneling, and feeding, and not sleeping or hibernating as commonly thought.
After the long 2 to 17 years, cicadas emerge from the ground as nymphs. Nymphs climb the nearest available vertical surface (usually a plant) and begin to shed their nymph exoskeleton. Free of their old skin, their wings will inflate with fluid (haemolymph) and their adult skin will harden (sclerotize). Once their new wings and body are ready, they can begin their brief adult life.
Adult cicadas, also called imagoes, spend their time in trees looking for a mate. Males sing (or otherwise vibrate the air or their surroundings), females respond, mating begins, and the cycle of life begins again."
