After leaves fall from trees, some types of damage that were once covered by foliage become visible. An example is the damage done to small tree stems by cicadas. Cicada nymphs live in the soil. In May, the brown wingless nymphs emerge from the soil and crawl up tree trunks or other objects. Their skin then splits in two halves and adult cicadas emerge. The males "sing" by vibrating two drum-like membranes on their bodies to attract females. After mating, the females cut slits in pencil-sized tree twigs and laid eggs. After 6 to 10 weeks, the eggs hatch and young cicadas fall to the ground.