Identification
The European earwig (Forficula auricularia) is a nocturnal insect easily identified by the pincers at the tip of its abdomen (the cerci). Contrary to popular belief, it does not enter human ears and it does not sting. In Quebec it lives mainly in the garden and comes indoors in the fall, drawn by moisture and warmth. Indoors, its presence is usually seasonal.
A mother that broods her eggs
The earwig is one of the few insects that shows active maternal care: the female broods her eggs in the fall and guards her young nymphs through their first weeks. That biological quirk explains why fall invasions near foundations often line up with family nesting sites.
-
AAbdominal pincers (cerci)
Curved in the male, straighter in the female. Used for defence, for catching prey and for folding the wings. Impressive to look at, but harmless to people.
-
BWings under short elytra
Two short wing cases covering complex, tightly folded membranous wings. It can fly but rarely does. The flattened body lets it slip under debris.
-
CFlat, dark brown body
Body 10 to 15 mm long, flattened top to bottom, reddish brown. Long slender antennae. Short legs built for a quick escape. Gives off a distinctive defensive odour when crushed.
Adult
Maternal care that is rare among insects: the female broods her eggs and guards her nymphs through the first instar. An omnivore, it eats both insects and plant matter.
Life cycle
HEMIMETABOLOUS · 3 STAGES · 1 YEARLaid in the soil in the fall in batches of 20 to 80. The female broods the eggs and turns them regularly to keep mould away. A genuinely unusual case of maternal care.
Four nymphal instars. Looks like the adult but without developed wings or pincers. Active in spring and summer, feeding the same way the adult does.
Active at night. Hides by day under stones, debris, bark and mulch. Moves into houses in the fall looking for warmth and moisture.
Do not confuse it with
The earwig is often mistaken for other night-active insects such as house centipedes or cockroaches, but its tail pincers are unique.
House centipede
Many long legs and very fast on its feet; no pincers at the end of the abdomen.
Rove beetle
Elongated beetle with short wing cases; raises its abdomen but has no pincers.
Signs of activity
Large numbers appearing at night
Suddenly finding many earwigs in the kitchen, bathroom or basement, usually in the evening. They come out of joints, cracks and damp drains.
In flower pots and compost
Clusters hidden under indoor flower pots, in kitchen compost or under damp mats. They gather wherever it is warm and humid.
Damage to houseplants
Ornamental leaves pierced or nibbled overnight. Tiny black droppings visible on and under the leaves. The damage looks much like slug damage.
Dozens of earwigs showing up indoors at once almost always follows a long spell of rain or the first cold nights of September and October. The wave is seasonal and passes on its own once entry points are sealed.
Treatment
Vegetable oil earwig trap
- 200 ml Vegetable oil (canola or olive) with 1 tsp of soy sauce The soy sauce draws earwigs in; the oil drowns them on contact
- Pour the mix into a 200 ml can. Set it flat on the floor in damp spots (under the sink, bathroom, basement). Check it in the morning, empty it and refill. Very effective during a fall invasion.
Earwigs do not last long in a dry environment. Fixing leaks, ventilating basements and clearing mulch away from foundations removes the pressure for good, far more effectively than an insecticide.
Check door and window seals, pipe penetrations, garbage chutes and floor drains. Any gap of 2 mm is a possible way in.
Turn over decorative stones, lift the mulch, check damp foundations and wood-to-soil contact points. Earwigs spend the day in these damp shelters before moving in.
Locate indoor moisture: under sinks, around plumbing, in basement cabinets and near door thresholds. Any lasting condensation draws them.
Prevention
- Keep mulch and plants off the foundation
Keep a dry 30 cm band clear of mulch, leaves and plants against the foundation. That buffer dries earwigs out before they reach the walls and the entry points.
ZONE 1 · FOUNDATIONS
Frequently asked questions
Are earwigs dangerous to people?
No. The earwig (Forficula auricularia) does not sting and is not venomous. Its pincers (cerci) are for defence and for handling prey; they do not break human skin.
Do earwigs crawl into your ears?
No, that is a myth. Earwigs do not live or lay eggs in the human ear canal; the name comes from an old folk belief with nothing behind it.
Why do I have them in the house?
They are looking for moisture and darkness: foundations, basements, bathrooms, under pots. High humidity around the house encourages them.
How do I get rid of them?
Dry out the damp areas, pull mulch and plant debris away from the foundation and seal the cracks. For a stubborn infestation, targeted treatment by an exterminator solves it at the source.