European Earwig

Forficula auricularia is a species complex comprising the common earwig. It is also known as the European earwig. It is an omnivorous insect belonging to the family Forficulidae. The name earwig comes from the appearance of the hindwings, which are unique in their resemblance to human ears when unfolded. The species name of the common earwig, auricularia, is a specific reference to this feature. The European earwig survives in a variety of environments. It is also a common household insect in North America. They are often considered a household pest because of their tendency to invade crevices in homes and consume pantry foods, though they may also act as beneficial species depending on the circumstances.

European earwigs are primarily nocturnal, emerging from daytime refuges such as under stones, bark, or leaf litter to forage at night. Their omnivorous diet includes decaying plant matter, fruits, flowers, seedlings, aphids, mites, and insect larvae. Foraging is typically solitary, but aggregations may occur in favorable microhabitats. Earwigs use their cerci for defense, prey capture, and intraspecific communication, with males engaging in ritualized combat using their forceps during territorial or mating disputes. They are capable of limited flight but rarely do so, relying instead on running to escape threats. When disturbed, they may release a foul-smelling secretion from abdominal glands as a deterrent. Earwigs are also known for their grooming behavior, which helps prevent fungal infections and maintain sensory function.

Reproduction in Forficula auricularia is characterized by a single annual breeding cycle in temperate regions. Mating typically occurs in late summer to early autumn, after which females excavate a nest chamber in the soil or under debris. Females lay 20–80 eggs in a cluster and exhibit extensive maternal care, guarding, cleaning, and turning the eggs to prevent desiccation and fungal growth. Incubation lasts about 1–2 months depending on temperature. Upon hatching, the nymphs remain with the mother for several days to weeks, receiving protection and food provisioning. The mother ceases care after the first molt, and the nymphs disperse to complete 4–5 molts before reaching adulthood. This subsocial behavior is relatively rare among insects and is a key adaptation for survival in unpredictable environments.

European earwigs possess several notable adaptations. Their forceps-like cerci serve multiple functions: defense against predators, prey capture, intraspecific competition, and courtship. The ability to fold their hindwings beneath short elytra allows for rapid deployment if flight is necessary, though flight is infrequent. Their nocturnal and crevice-dwelling habits reduce predation risk and desiccation. The production of chemical secretions from abdominal glands provides an additional defense mechanism. Subsocial maternal care enhances offspring survival, especially in variable climates. Their omnivorous diet and tolerance for a wide range of microhabitats contribute to their ecological success and invasiveness.

The European earwig has a long-standing presence in European folklore and superstition, often associated with the erroneous belief that it enters human ears to burrow into the brain—a myth reflected in its common name. In reality, such behavior is extremely rare and not characteristic of the species. Earwigs have also appeared in literature and art as symbols of discomfort or pestilence. In some cultures, they are regarded as beneficial garden allies due to their predation on aphids and other pests. There are no known traditional medicinal or culinary uses for this species.

Recent genetic research has revealed that Forficula auricularia is a species complex, with at least two cryptic lineages (A and B) differing in reproductive biology and distribution, particularly in North America. Studies on maternal care have provided insights into the evolution of social behavior in insects, with earwigs serving as a model for subsociality. Ongoing research is investigating the ecological impact of earwigs in agricultural systems, their role as both pests and beneficial predators, and their responses to climate change and habitat modification. Chemical ecology studies have characterized the defensive secretions used against predators and pathogens.

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The European Earwig is currently classified as Least Concern on the IUCN Red List.

Currently, Forficula auricularia is not considered threatened and is classified as Least Concern by conservation authorities. Its populations are stable or expanding in many regions, particularly in areas where it has been introduced. However, localized threats include pesticide use, habitat disturbance, and competition with native earwig species. In agricultural settings, earwigs can become pests by feeding on soft fruits, seedlings, and flowers, leading to economic losses. Conversely, their predation on aphids and other pest insects can benefit crop health. Human perception of earwigs as pests often leads to control measures that may impact non-target species.