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Forficula auricularia has an elongated flattened brownish colored body, with a shield-shaped pronotum, two pairs of wings and a pair of forcep-like cerci. They are about 12–15 mm long. The second tarsal segment is lobed, extending distally below the third tarsal segment. The antenna consists of 11–14 segments, and the mouth parts are of the chewing type. Adult males are polymorphic in body weight and head width, as well as cercus length and width. The male forceps are very robust and broadened basally with crenulate teeth. The female forceps are about 3 mm long, and are less robust and straighter. The cerci are used during mating, feeding, and self-defense. Females also have tegmina of about 2 mm in length. Third instar or older nymphs that have lost one branch of cerci are capable of regenerating it in form of a straight structure. Males with asymmetrical forceps are called gynandromorphs or hermaphrodites because they resemble females.
Native to Europe, western Asia and probably North Africa, Forficula auricularia was introduced to North America in the early twentieth century and is currently spread throughout much of the continent. In North America, European earwigs comprise two sibling species, which are reproductively isolated. Populations in cold continental climates mostly have one clutch per year, forming species A, whereas those in warmer climates have two clutches per year, forming species B. European earwigs are most commonly found in temperate climates, since they were originally discovered in the Palearctic region, and are most active when the daily temperature has minimal fluctuation.[14