Ground cover, mulch, and plastic sheeting on the ground are the favorite hangouts for those “pincher bugs”, properly known as European Earwigs, these little bugs like to travel … especially at night and they will show up inside our houses with distressing regularity.
Earwigs do not bite or sting. They carry no diseases and do not infest food, destroy wood, damage fabrics, or in any way feed on people or pets. So why do they come inside the house? To answer this question, let’s look at how earwigs live and breed.
Most insects have a four stage life cycle; egg, larvae, pupae, and adult, like ants, bees, and butterflies. Earwigs have what is called a gradual metamorphosis, like termites and cockroaches they develop in stages called “instars”. The younger stages are called “nymphs” and are, unsurprisingly, smaller than the fully grown reproductive adults; with each instar the nymph will molt (cast off its outer shell/skin) and grow into the next stage of development until they become reproductive adults. Earwigs prefer cool temperatures and moist conditions that they find in mulch and many types of ground cover. Females will typically lay thirty to sixty eggs and will guard them until well after they hatch into nymphs. After the first instar the nymphs are on their own and will often become a meal for crickets or other earwigs.
Whether nymph or adult, they will eat organic debris, other bugs, each other, and some types of fruit and garden plants. In your garden or yard, they tend to feed on aphids, psocids, mites, and bug eggs and larvae that they might find, so they are beneficial in that regard. European earwigs normally do not like to be inside your house; they prefer moist conditions and a ready food source that they do not find on tile and carpets and that is why you will find them wandering aimlessly around the floor when they do make it inside. Like cockroaches, they are attracted to tight places with plenty of moisture.
They sometimes hang out together, but earwigs are not considered social insects in that they do not have common nesting areas, queens, or any other of the other social behaviors that you would expect in a bee hive or an ant colony. All of the adults are reproductives; male or female, and they can and will mate and lay eggs whenever the conditions are right as they so often are here in North County.
Why do earwigs go indoors?
When it gets too hot or too dry the earwigs, crickets, centipedes, and scorpions start looking for a better place to live; they move from the canyons to irrigated communities and we start getting calls about bugs indoors. For the most part they are looking for moisture and a safe place to hang out. Controlling earwigs indoors is usually just a matter of excluding them. Whenever they appear inside you should look for how they are getting in. Many times it is because of sliding glass doors with worn or missing pads on the bottom. Check the bottoms of all doors and keep them shut, especially in the evenings.>
On the outside you will need to remove earwig breeding sites if you want to be rid of them. During the hot dry weather of summer they will travel up to a quarter of a mile overnight looking for moisture and a place to breed. Some of them will end up indoors if they can find a way.
An organic farmer will reduce the earwig population around her garden by luring the insects into an upturned flower pot. She fills the pot with crumpled straw or newspaper and places it in a moist, shady area. The earwigs will shelter in this during the day and can be killed by placing the pot in a black plastic bag in the sun for a day.