Earwigs are a common sight that many people encounter, often leading to confusion due to their resemblance to other insects. Despite their intimidating appearance, understanding their specific features and those of their look-alikes helps in accurate identification. This guide aims to clarify these distinctions.
Understanding Earwig Appearance
Earwigs are insects belonging to the order Dermaptera, with unique physical traits. Most earwig species are elongated with flattened bodies, ranging from about 0.2 to 2 inches (5 to 50 mm) in length, though some can be larger. Their coloration varies from pale brown to reddish-brown or dark brown to black. They possess six legs and a pair of thread-like antennae up to half their body length.
Earwigs are defined by prominent, pincer-like appendages, called cerci, at their abdomen’s rear. These hardened, unsegmented cerci vary in shape between sexes; males have more curved pincers, while females have straighter ones. Most earwigs have two pairs of wings: short, leathery forewings covering larger, membranous hindwings, though many species rarely fly.
Common Look-Alikes and Their Distinguishing Features
Several insects share superficial similarities with earwigs, leading to frequent misidentification. Rove beetles are often mistaken for earwigs due to their elongated bodies and similar size and color. A key difference is their wing covers: rove beetles have very short elytra that expose most of their abdomen, and they lack the distinct pincer-like cerci of earwigs, possessing only small appendages at their abdomen’s tip.
Silverfish are another insect sometimes confused with earwigs, with distinct differences. Silverfish are wingless, are silvery-gray, soft-bodied, and teardrop-shaped. Instead of pincers, they have three long, tail-like appendages (caudal filaments) at their abdomen’s end, softer and more hair-like than an earwig’s cerci. Their movement is a wiggling, fish-like motion.
Crickets, especially camel crickets, can be confused with earwigs due to long antennae and body shape. Crickets, however, have long hind legs adapted for jumping and lack the prominent pincer-like cerci. Instead, they have two slender cerci and, in females, an ovipositor—a tube-like organ for laying eggs.
Additional Clues for Accurate Identification
Beyond physical features, observing an insect’s behavior and habitat provides valuable clues for identification. Earwigs are nocturnal, active at night. They hide in small, dark, often moist places during the day, such as under rocks, logs, leaf litter, or in crevices. They seek shelter indoors when outdoor conditions become too dry, hot, or cold.
When disturbed, earwigs scurry quickly to find cover. While they have wings, many species rarely fly, preferring to run or use short bursts of flight. Their pincers are used for defense, capturing prey, and even in courtship. Some species emit a foul-smelling liquid as a deterrent when threatened. Understanding these behavioral patterns helps confirm whether you are observing an earwig or a different insect.