Earwigs belong to the insect order Dermaptera, characterized by their distinctive, forcep-like appendages at the tail end of the abdomen. These insects are common inhabitants of gardens and moist environments worldwide, often causing concern due to their intimidating appearance and tendency to suddenly appear indoors. Assessing whether the earwig is a true pest depends on its population density and the specific environment it inhabits. Understanding their biology and behavior is necessary to assess the threat they pose to gardens, structures, and human well-being.
Identifying Earwigs and Addressing Safety Concerns
Earwigs are easily recognized by their elongated, reddish-brown bodies, which typically measure between one-quarter and one inch long. Their most notable feature is a pair of prominent pincers, scientifically called cerci, located at the rear of the abdomen. The shape of these cerci varies between sexes; males display curved, more pincer-like appendages while the female’s are straighter and more slender. These nocturnal insects use their cerci primarily for defense against predators, sparring with rivals, and holding prey, not as a weapon against humans.
The common name, derived from the Old English for “ear wiggler,” fueled a persistent, unfounded myth that the insects crawl into sleeping people’s ears to bore into the brain. This folklore is baseless, as earwigs prefer dark, damp crevices in the soil or under debris. While their pincers can deliver a slight, harmless pinch if handled, earwigs are not venomous and do not transmit diseases to humans. They are generally classified as nuisance pests because of their appearance and occasional invasion of homes.
Assessing Damage in Gardens and Structures
The pest status of earwigs is most apparent in the garden, where they are omnivorous feeders that consume both decaying matter and living plant tissue. They are particularly damaging to tender young seedlings, which they can completely defoliate overnight, leading to plant death. On mature plants, their feeding results in small, irregular holes or ragged edges on leaves and petals, most noticeable on flowers like marigolds, roses, and dahlias.
Earwigs also target soft fruits and vegetables, causing shallow gouges in produce such as strawberries, apricots, and peaches. In sweet corn, they feed on the developing silks, which can interfere with pollination and result in poorly formed kernels. However, earwigs also feed on aphids, mites, and other small insect pests, sometimes providing a beneficial role in natural pest control. The damage they cause is only economically significant when populations become large or when they target high-value crops.
When conditions outside become too dry, hot, or excessively wet, earwigs seek shelter inside structures, transforming their status into a household nuisance. As moisture-loving insects, they are often found in damp areas like basements, laundry rooms, and crawl spaces. While they do not breed indoors, a large number entering a home can be highly bothersome. Their presence can also indicate a moisture problem within the structure, such as a leaky pipe or poor drainage near the foundation.
Strategies for Control and Prevention
Effective earwig management begins with modifying the external environment to make it less hospitable. Since earwigs seek out cool, dark, and damp locations during the day, removing hiding spots is the primary control measure. This involves clearing away organic debris, such as leaf piles, excess mulch, and stored wood, particularly those resting against the foundation. Creating a dry, bare strip of ground, six to twelve inches wide, around the perimeter of a building will discourage them from approaching and entering the structure.
Exclusion is an important preventative strategy to keep earwigs from moving indoors. Sealing cracks and gaps in the foundation, around window frames, and under doors prevents easy access. Reducing indoor moisture by fixing leaky faucets and utilizing dehumidifiers in basements also eliminates the conditions that attract them.
Non-chemical removal methods are highly effective for reducing garden populations without harming beneficial insects. Simple traps, such as rolled-up damp newspapers or short sections of garden hose placed in the garden overnight, will attract earwigs seeking shelter. The insects can then be collected in the morning and disposed of in soapy water. Low-sided cans sunk into the soil and filled with vegetable oil and a drop of bacon grease or fish oil also serve as efficient pit traps.
Chemical treatments are generally considered a last resort and are typically applied as a barrier around the exterior foundation. Insecticides containing active ingredients like pyrethrins or bifenthrin can create a protective perimeter, but they should only be used after exclusion and environmental modification methods have been implemented. Focusing on the reduction of moisture and hiding places remains the most sustainable and effective approach to long-term earwig control.