YOU may groan or cover your ears when you hear cicadas, but one thing is for certain — you know it's summer.
Cicadas are one of the loudest insects in the world.
The males sing in a chorus, reaching 120 decibels, loud enough to be painful to the human ear at close range.
Male cicadas are so loud they can even block their hearing when they call, so that they don't deafen themselves.
Some types sing at so high a pitch that you can't even hear them.
But don't worry about the ear plugs — they call for only a few weeks when the males attract mates for breeding, after spending six or seven years underground.
Adults cling to tree branches and trunks, or low shrubs and long grasses this month.
Underground, the nymphs shed their skin as they grow, and after they dig their way out they shed their skin one last time before becoming a fully-winged adult.
There are about 2500 known species of cicadas in the world with Australia home to 200 species with names such as Black Prince, Double Drummer, Floury Baker, Cherry Nose and Razor Grinder.
Cicadas have long mouthparts to pierce and suck sap from plants but do very little damage to gardens.
Cicadas in and around Sydney are having a bumper year, emerging in largest numbers since 2006.
Black Princes and Floury Bakers start off at the end of December and go right through to February or March. Red Eyes can still be found in the middle of February.
Cicadas are food for bats, birds, spiders, ants, mantids, tree crickets and wasps.
■ CICADAS are considered a great food source. They were eaten in Ancient Greece, as well as China, Malaysia, Burma, South America and the Congo for skewering, deep frying and stir frying.
■ Despite its sap-sucking mouthpart, it won't sting you.
■ Cicada legs have strong hooks which help them stay attached to trees and plants so be careful when handling them as they can scratch.
■ So prominent in Australia are cicadas that most of their common names were given to them by children.
■ Different species of cicadas have different songs.