Earwigs, often called “pincher bugs,” are common insects that can appear in large numbers. Understanding their biology and preferred environments helps explain their prevalence.
Understanding Earwigs
Earwigs are insects from the order Dermaptera, recognizable by the forceps-like pincers, called cerci, at the end of their abdomen. Their bodies are often flat and narrow, allowing them to fit into small spaces.
A common myth suggests earwigs crawl into human ears to lay eggs or burrow into the brain. This is a misconception, though they may accidentally enter an ear if a person is sleeping in their habitat. Earwigs are largely harmless to humans; they do not sting, are not venomous, and do not transmit diseases. While their pincers can deliver a mild pinch if provoked, it rarely breaks the skin. These insects are primarily nocturnal, seeking dark, damp, and undisturbed places during the day.
Factors Contributing to High Populations
Earwig populations surge due to specific environmental conditions that provide ample food and suitable shelter. They thrive in moist environments, with prolonged wet weather, such as humid summers or rainy seasons, favoring their reproduction and survival. Earwigs require moisture to prevent dehydration.
Earwigs are omnivores, feeding on a diverse diet including decaying organic matter, live plants, and other small insects. They consume decaying vegetation like leaves, fruit, and fungi, and also prey on aphids, mites, and slugs. Abundant food sources, combined with damp hiding spots, attract them in large numbers. They seek shelter in dark, damp crevices such as under rocks, logs, mulch, leaf litter, and in cracks in foundations or under potted plants. When these conditions are widespread, it creates an ideal breeding ground, leading to noticeable increases in their populations.
Managing Earwig Presence
Controlling earwig populations begins with modifying their preferred habitat. Reducing moisture around the home is important, including fixing leaky pipes, improving drainage, and cleaning gutters. Using dehumidifiers in damp areas like basements and crawl spaces also helps reduce humidity.
Removing organic debris near the home’s foundation eliminates many hiding spots. This involves clearing leaf piles, excessive mulch, and woodpiles, as these provide both shelter and food sources. Creating a bare soil barrier between garden beds and the foundation can also make the area less appealing. Sealing entry points into the home, such as cracks in foundations, gaps around windows and doors, and unscreened vents, prevents earwigs from seeking indoor refuge.
For existing populations, simple, non-toxic methods are effective. Traps made from rolled-up newspapers, cardboard, or sections of garden hose attract earwigs seeking shelter; these can then be collected and submerged in soapy water. Oil pit traps, using vegetable or fish oil, also attract and drown them. Diatomaceous earth, a natural powder, can be sprinkled in areas where earwigs are found, dehydrating them upon contact.