Earwigs (Order Dermaptera) are common insects found across the globe, often recognized by their distinctive appearance. This group of 2,000 species is mostly nocturnal, spending daylight hours hidden in small, moist crevices. Though they are a familiar sight in gardens and occasionally homes, earwigs are frequently misunderstood. Their behavior and role in nature are complex, extending far beyond the perception of them as mere household pests.
Identifying Characteristics and Common Misconceptions
The most noticeable physical trait of an earwig is the pair of forceps-like appendages, called cerci, extending from the end of the abdomen. These cerci function in defense, capturing prey, and assisting in folding their rarely used wings beneath the short forewings. The cerci on a male earwig are notably curved, while those on a female are generally straighter.
The name “earwig” has unfortunately perpetuated the myth that these insects intentionally crawl into human ears to lay eggs or burrow into the brain. This folklore is entirely untrue. While an earwig might accidentally crawl into an ear canal, this occurrence is extremely rare and unintentional, as they are simply drawn to the cool, damp shelter that a small crevice provides during the day.
The Earwig’s Role in the Ecosystem
Earwigs are omnivorous, meaning their adaptable diet includes both plant matter and other organisms. They serve as decomposers by consuming decaying organic material, such as rotting wood, fallen leaves, and debris. This scavenging behavior helps break down organic matter, contributing to the recycling of nutrients back into the soil.
As predators, earwigs actively hunt and consume soft-bodied garden pests like aphids, mites, and insect eggs, helping to regulate pest populations. However, high earwig populations can sometimes transition into pest activity by chewing on tender plant shoots or ripe fruits. This shift usually occurs when preferred food sources, like other insects or decaying matter, become scarce.
Earwig Life Cycle and Unique Maternal Behavior
The earwig life cycle involves a simple metamorphosis with three stages: egg, nymph, and adult. Females typically lay clutches of 20 to 80 eggs in underground burrows during the cooler months. Nymphs resemble smaller versions of adults but lack fully developed wings and cerci, undergoing several molts before reaching maturity.
A distinctive characteristic is the sophisticated maternal care displayed by the females, a trait uncommon in non-social insects. The mother remains in the burrow to guard her eggs, defending them from predators, and meticulously cleaning them to prevent fungal growth. This cleaning involves applying chemical substances that inhibit mold infection. She continues to tend to the young nymphs after they hatch, providing food and protection until they undergo their second molt and become more self-sufficient.
Management and Prevention Around the Home
Earwigs primarily enter buildings when the outdoor environment becomes too dry or too wet, seeking moisture and shelter. They gain entry through small gaps, cracks in foundations, or around utilities, gravitating toward damp areas like basements or laundry rooms. Effectively managing their presence indoors centers on reducing the environmental conditions that attract them.
Fixing leaky pipes, ensuring proper drainage around the foundation, and using dehumidifiers in damp rooms will discourage their presence. Outside the home, removing moist debris like leaf piles, excessive mulch, or rotting wood from the perimeter eliminates their preferred daytime hiding spots. Simple, low-toxicity control methods include rolling up a damp newspaper near entry points as a trap, or using a spray solution of dish soap and water on active areas.