Cicadas, which can measure over an inch in length and emerge in sudden, massive numbers, often cause public concern due to their sheer presence and startling appearance. Their large size and the loud, whirring sound of the males’ mating calls lead many to wonder if these insects pose any physical danger. This apprehension is common, especially during the synchronized emergence events of periodical cicada broods. This information clarifies whether these abundant insects can bite or sting and explains the true nature of their interaction with humans.
The Direct Answer: Cicadas Do Not Bite Humans
Cicadas are completely harmless to humans and pets; they do not sting and are not venomous. They lack the anatomical structures necessary to deliver a defensive sting or an aggressive bite. Unlike insects with mandibles, or chewing mouthparts, cicadas are not equipped to consume solid material. They are not interested in humans or animals as a food source, so their presence should not cause panic.
Adult cicadas have no stingers, and the females’ egg-laying apparatus, called an ovipositor, is not used for defense. While they possess sharp, pointed body parts, the rare sensation of being “bitten” is typically a mistaken identity. The insect’s focus is solely on mating and feeding from plants, not on causing harm to passersby during their short adult life stage.
Understanding Cicada Mouthparts and Feeding
The mouth structure of a cicada is highly specialized, classifying them as piercing-sucking insects in the order Hemiptera. Instead of jaws, they possess a long, straw-like tube called a proboscis, or beak, which is normally tucked beneath their head. This proboscis contains four needle-like stylets that are used to penetrate plant tissue.
Their diet consists exclusively of xylem fluid, which is the water and nutrient solution transported within the vascular system of trees and woody shrubs. The tip of the proboscis, which pierces the wood, is reinforced to increase hardness, allowing it to penetrate tough surfaces. When a cicada lands on a person, it may occasionally probe the skin with this beak, mistaking the skin for a plant surface. This accidental probing feels like a quick, clumsy poke, but the insect is not trying to draw blood and is incapable of inflicting a serious wound.
Cicadas: A Nuisance, Not a Threat
The primary impact of a cicada emergence is the overwhelming noise created by the males’ mating calls. This loud acoustic activity is a short-lived nuisance, but it does not pose a physical threat to health. Cicadas are not known to transmit diseases to humans, pets, or other animals, unlike other common flying insects.
The only real damage cicadas cause is to young trees and shrubs. Female cicadas use their hardened ovipositors to cut small, slit-like incisions into pencil-sized branches to deposit their eggs. This activity can cause the ends of the branches to wilt and die, a symptom known as “flagging.” While this damage is rarely a concern for mature, established trees, it can be a problem for young, newly planted saplings.