Cicada on tree trunk IMG 3756 - These strange creatures make the loudest sounds of any insects in the world, and when large numbers of them thrive in a eucalypt forest the noise, on a summer's day, can be painful to the ears. Cicadas spend most of their lives underground, and this can be a period of up to 10 years. They eventually emerge from a hole in the ground and clamber up the nearest tree or vertical object where their metamorphosis sees them become a winged insect. Females lay their eggs in a slit in the bark of a tree, and soon after hatching, the tiny nymphs fall to the ground to conceal themselves in the soil until the time comes to emerge and begin the cycle of life - and noise - once again. There are around 200 species of cicadas in Australia.