Cicadas damage many ornamental and hardwood trees. Oaks are commonly attacked but the most seriously damaged are newly planted fruit and ornamental trees such as apple, dogwood, peach, plum, pecan, cherry, and pear. Pines and other conifers are not commonly attacked. Cicadas are not poisonous and do not have a stinger. Communities and farms with large numbers of cicadas emerging from the ground often are beset with a substantial noise problem. Half of the population are males "singing" or calling for the females. Egg laying by the female cicadas causes significant damage to small twigs. These twigs will die because the branch is split when the eggs are placed under the thin bark. The immature cicadas, called nymphs, do not feed on the twig where they hatch but drop to the ground and burrow to the root system below the tree. Damage caused by nymphs feeding on plant roots is considered very minor. Once attached they stay on the root for 13 or 17 years until the next emergence.