Earwigs belong to the insect order Dermaptera, recognizable by the pair of forceps-like pincers, or cerci, extending from their abdomen. They are generally harmless to humans, feeding primarily on decaying organic matter. An earwig infestation occurs when a high volume of these insects suddenly appears inside a home, causing annoyance. This sudden appearance is caused by an environmental imbalance outdoors that drives the earwigs to seek immediate shelter and moisture within the structure.
Essential Environmental Conditions
Earwigs have a fundamental biological need for moisture and quickly lose water in dry conditions. This requirement dictates their outdoor habitat, which typically consists of damp soil, leaf litter, mulch, or other debris near a home’s foundation. High populations congregate in these areas where moisture is consistently available, such as around leaky outdoor faucets, air-conditioning units, or under downspouts that deposit water too close to the structure.
Decaying organic matter further attracts earwigs, providing a readily available food source. Thick layers of landscape mulch placed directly against the house create a cool, dark microclimate for them to hide during the day. Woodpiles, old boards, and dense ground cover near the foundation also serve as daytime harborage areas. These outdoor conditions create a staging area where large numbers of earwigs gather and reproduce right at the perimeter of the house.
The outdoor population actively seeks new shelter when the exterior environment becomes inhospitable, leading to an indoor invasion. Periods of prolonged heat and drought prompt earwigs to migrate indoors in search of cooler, damp refuge. Conversely, heavy rains or flooding of their outdoor shelters can also force them toward the dry safety of a home’s foundation and interior spaces.
Common Structural Entry Points
Once conditions outside force earwigs toward the structure, they exploit any available physical weakness to enter the dwelling. Earwigs have a flattened body shape that allows them to squeeze through incredibly small openings, sometimes less than one-eighth of an inch wide. They typically enter homes at ground level through cracks and crevices in the foundation walls.
Gaps around poorly sealed doors and windows, especially those in basements or lower levels, provide direct access points. Missing or damaged door sweeps and weatherstripping offer a clear path for the insects to crawl into the home. Utility line entry points, where pipes or wires penetrate the exterior wall, are also commonly used routes if the seal is not secure.
Earwigs can also be accidentally carried inside on items brought in from the outdoors. They may harbor in firewood stacked against the house, potted plants, cardboard boxes, or bundles of newspapers that have been sitting in a damp area. They may also be drawn to bright outdoor lights at night, causing them to congregate near doors and windows and increasing the likelihood of them slipping inside.
Removing Sources of Attraction
Addressing an earwig problem requires modifying the outdoor environment to make the perimeter less hospitable. Improving drainage is a primary step, which involves ensuring that rain gutters and downspouts direct water away from the foundation. Fixing leaky spigots, pipes, and air conditioning condensation units near the house eliminates concentrated sources of moisture in the soil.
Reducing organic debris and ground cover near the foundation removes their preferred daytime hiding spots and food sources. This means pulling back landscape mulch at least 12 to 18 inches from the foundation wall to create a dry, exposed barrier. Removing piles of leaf litter, grass clippings, and old boards or woodpiles from the immediate vicinity of the home is also necessary.
A proactive measure involves sealing the physical entry points to prevent accidental indoor migration. Applying caulk to cracks and gaps in the foundation walls and around window frames eliminates the tiny routes earwigs use to enter. Installing or repairing door sweeps and weatherstripping on all exterior doors, especially those at ground level, closes the most common access points.