Earwigs are common insects found globally, easily recognized by the prominent, forceps-like pincers (cerci) extending from their abdomen. These dark brown, elongated insects typically range from a quarter-inch to an inch in length. Their appearance, especially inside a home, signals specific environmental conditions conducive to their survival. Understanding what attracts these nocturnal insects provides homeowners with insight into potential maintenance issues that require attention.
Identifying Earwigs and Their Natural Environment
Earwigs possess three body sections and six legs. The cerci are significantly curved in males and straighter in females. While some species have wings, they are generally poor fliers and prefer to crawl. They are nocturnal, seeking sheltered, dark places to hide during the day.
Their preferred outdoor habitats are consistently cool, dark, and damp locations where they can find moisture and food. Common hiding spots include under rocks, logs, boards, dense ground cover, leaf litter, or mulch. These environments provide the high humidity and shelter necessary to prevent desiccation. Earwigs are omnivorous, feeding on decaying organic matter, fungi, and other insects like aphids.
The Environmental Conditions They Indicate
The presence of earwigs indoors is a clear indicator of excessive moisture or high humidity within the structure. Earwigs are highly sensitive to changes in environmental dampness and will actively seek refuge when outdoor conditions become either too dry or overly saturated from heavy rain. They are frequently found in wet basements, poorly ventilated crawlspaces, and around leaking pipes in kitchens or bathrooms, which offer the humid conditions they require.
A congregation of earwigs also signals the presence of decaying organic matter, which serves as a food source. This can include moldy wood, wet cardboard boxes, or accumulated debris near the foundation, such as leaves in gutters. Furthermore, their entry points signal structural vulnerabilities, as they crawl inside through small cracks in the foundation, gaps around doors and windows, or poorly sealed vents.
Assessing the Risk and Damage Potential
Despite their intimidating appearance, earwigs pose no threat to human health and are not known to spread disease. Their abdominal pincers are used for defense, mating, or capturing prey, but are generally too weak to break human skin. Indoors, they are considered nuisance pests due to their unpleasant appearance and the foul-smelling, yellowish-brown liquid they secrete when crushed or alarmed.
Earwigs do not consume sound wood or cause direct structural damage like termites. However, their presence near wood highlights existing moisture damage or rot, which is the true threat to the home’s integrity. Outdoors, large populations can damage tender seedlings, soft fruits, and flowers. They also have a beneficial role in the garden ecosystem, preying on pests like aphids and mites.
Home Exclusion and Management Strategies
Successful management focuses on eliminating the underlying environmental conditions that attract earwigs. The most effective strategies are:
- Reduce moisture levels by fixing plumbing leaks and ensuring gutters properly direct water away from the foundation.
- Improve ventilation in damp areas like basements and crawlspaces, often using a dehumidifier, to make the indoor environment less hospitable.
- Remove outdoor harborage sites near the home’s perimeter, such as clearing woodpiles, leaf litter, and excessive mulch away from the foundation to create a dry, bare zone.
- Seal potential entry points by caulking cracks and crevices in the foundation and around utility lines.
- Install tight-fitting door sweeps and window screens to block common routes of entry.