About Earwigs
Earwigs are nocturnal insects commonly found in moist, shaded environments. Although their appearance is often alarming due to the prominent pincers at the end of their abdomen, earwigs are primarily nuisance pests rather than harmful insects. They are frequently encountered around gardens, landscaping, and occasionally inside homes when environmental conditions shift.
Physical Characteristics of Earwigs
Earwigs range from 1/4” to 1”, depending on the species. They are typically reddish-brown to dark brown and have elongated, flattened bodies. Their most recognizable feature is the pair of forceps-like pincers—called cerci—located at the end of the abdomen.
Earwigs possess:
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Six legs and a segmented body
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Long, slender antennae
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Wing structures, though many species seldom fly
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Curved cerci in males and straighter cerci in females
Nymphs resemble smaller versions of adults and undergo several molts as they mature.
Earwig Appearance in California
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The European earwig, the most widespread species in California, has straight or slightly curved cerci and a reddish-brown body.
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The ring-legged earwig, found in warmer regions of the state, has striped legs and a darker thorax.
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Size and coloration may vary more in coastal or irrigated landscapes due to humidity.
Moisture Dependence and Nocturnal Behavior
Earwigs are strongly associated with moisture. They thrive in environments that provide consistent humidity and shelter from sunlight. During the day, they hide in dark, protected spaces and emerge at night to feed.
Typical nighttime feeding includes:
- Decaying plant matter
- Fungi and algae
- Insects or arthropods
- Seedlings, flowers, or soft vegetation
Although they may feed on plants, earwigs rarely cause significant damage unless populations grow unusually large.
Behavior Patterns in California
- Coastal regions with consistent marine moisture support high earwig activity.
- Irrigated suburban landscapes—common throughout California—create ideal hiding and feeding environments.
- Hot, dry inland summers often drive earwigs into structures seeking moisture.
- Nocturnal activity may increase following warm evenings, irrigation cycles, or periods of rainfall.
Where Earwigs Live and Hide
Earwigs prefer environments that offer moisture, shelter, and organic debris. Outdoors, they commonly inhabit:
- Mulch beds
- Moist soil
- Under stones, logs, and potted plants
- Yard debris and leaf litter
- Shaded landscape borders
- Crevices in wood, brick, or retaining walls
Indoors, earwigs typically appear near moisture sources or protected hiding spots.
Common indoor locations include:
- Bathrooms
- Laundry rooms
- Kitchens
- Baseboards and wall voids
- Garages
- Utility areas
Habitats Frequently Seen in California
- Irrigated gardens and planters, especially in coastal and suburban homes
- Moist crawl spaces in older or coastal properties
- Wooded foothill regions, where shade and organic matter accumulate
- Mulched commercial landscapes, which retain moisture year-round
- Areas with drip irrigation, common in Central and Southern California
Seasonal Movement and Entry Into Structures
Earwigs often move indoors when outdoor conditions become unfavorable. The two primary triggers are:
- Hot, dry weather, which reduces moisture in soil
- Heavy rains, which flood their shelter areas and force them upward
Earwigs enter structures through:
- Gaps around doors
- Foundation cracks
- Weep holes
- Vents
- Utility penetrations
- Damaged weatherstripping
Once inside, they do not typically establish long-term infestations but may accumulate in damp or cluttered areas.
Entry Patterns in California Homes
- Inland regions often report spikes in indoor earwig activity during late summer heat waves.
- Coastal communities may see indoor entry during extended periods of fog followed by dryness.
- Homes near dense landscaping or mulch experience higher entry rates.
- Properties backing up to greenbelts, canyons, or wooded areas may see seasonal increases.
What Are the Risks of Earwigs?
Earwigs are largely nuisance pests. Their pincers may look intimidating, but are primarily used for defense or capturing small prey. While they can pinch if handled, the pinch is generally mild and does not pose health risks.
Potential issues include:
- Minor plant damage in gardens or landscape beds
- Accumulations indoors, especially in damp areas
- Unpleasant odors when large numbers gather
- Attraction of predators, such as spiders and beetles
Earwigs do not transmit diseases to humans and do not infest food sources or cause structural damage.
Earwig-Related Concerns in California
- Populations often increase following warm winters or higher-than-average rainfall.
- Dense suburban landscaping, common throughout California, creates ideal shelter zones.
- Moisture-rich environments near coastal counties support sustained activity.
- Seasonal weather shifts cause predictable indoor migration, particularly in Central Valley and inland Southern California.