Earwigs belong to the insect order Dermaptera, which includes about 2,000 species worldwide. These common insects are easily recognized by the prominent, forceps-like appendages extending from the rear of their abdomen. They are generally small, dark-colored, and flat-bodied, preferring to hide in dark, moist environments during the day and emerging at night. Public interest often focuses on the potential danger these distinctive appendages pose to humans.
Clarifying the Threat: Pinching Versus Biting
Earwigs primarily defend themselves by pinching, using the forceps-like structures on their tail. If an earwig feels threatened, such as when being picked up or accidentally squeezed, it may quickly grasp with these appendages. The resulting sensation is a brief, startling pinch that is rarely strong enough to break human skin. If the skin is punctured, the wound is minor and should be treated with basic first aid to prevent secondary infection.
Earwigs technically possess mandibles, or chewing mouthparts, but they are not aggressive biters and do not use them for defense against people. Any contact between an earwig’s mouth and human skin would be incidental and medically insignificant. They are not venomous and do not transmit diseases to humans or pets. The only risk they pose is the temporary discomfort of a defensive pinch.
Understanding the Pincer Anatomy and Function
The prominent rear appendages of the earwig are called cerci, which are hardened, unsegmented structures that function as forceps. These cerci are grasping tools used for a variety of purposes beyond simple defense. Earwigs use these structures to help fold their large, membranous hindwings beneath their short, leathery forewings after flight. The cerci are also employed in catching and holding prey for feeding.
A notable difference exists between the cerci of male and female earwigs, a characteristic known as sexual dimorphism. Male earwigs typically have larger, more curved, or caliper-like cerci, which they utilize in aggressive wrestling matches with rival males for dominance and mating rights. Conversely, female earwigs possess straighter, more scissor-like cerci, which are more effective for defensive jabbing against predators. The primary function of the cerci in both sexes is protection and intraspecies interaction, not aggression toward humans.
Earwigs: Dispelling Common Myths and Fears
The most persistent myth is the belief that earwigs crawl into the ears of sleeping people, a misconception that is the source of their common name. While “earwig” derives from Old English terms translating to “ear creature,” there is virtually no medical or scientific evidence to support this folklore. Earwigs are nocturnal and seek dark, moist crevices for shelter, but they do not actively pursue the human ear canal as a habitat. The notion that they burrow through the ear into the brain to lay eggs is completely unfounded.
The actual threat posed by earwigs is negligible, and they are considered nuisance pests. They may occasionally damage garden plants, feeding on tender sprouts, flowers, and soft fruits. However, they also offer some benefit by preying on other small insects and mites. Earwigs are primarily scavengers and omnivores, feeding on decaying plant and animal matter. They pose no significant health risk to people, and their presence in a home usually indicates an underlying moisture problem.