Occasional Invaders enter your home when the conditions outside become less than ideal for them. Once inside your home, most of these pests will not survive long periods of time indoors, leaving you to clean them up. Below are some of the most common Occasional Invaders here in Iowa that might make their way into your home.


Box elder bugs are black-winged insects with 3 red stripes running lengthwise down the body. The underside of their wings is bright red. Immature box elder bugs (nymphs) are wingless, smaller, have more round shaped and are bright red in color.  Box elder bugs are commonly found on elm, maple and box elder trees.  They are also commonly found congregating on houses and structures—usually on the south side—during warm days.  Box elders will typically appear during winter in cracks and crevices around buildings, door and window frames, behind siding and soffits, tree holds, woodpiles, etc.


The camel cricket ranges from light to dark brown in color, and may have lighter or darker mottled areas. It has a humpback and long, threadlike antenna that are much longer than the body. The camel cricket is typically found outdoors around buildings under mulch, stones, woodpiles and in other cool, moist areas. If indoors, they may be found in basements, utility rooms, crawl spaces, garages, etc. The camel cricket is nocturnal and will move indoors when it gets too hot and dry for them outside.


These long, worm-like creatures vary from yellowish to dark brown in color and may have darker stripes or markings. The first pair of their legs are modified clawlike “poison jaws”. They have anywhere from 15 to 177 pairs of legs, with 1 pair of legs on each segment. All centipedes have venom used to kill prey. The larger species can bite humans, resulting in a painful, bee-like sting. Centipedes are typically found in damp areas such as under mulch, grass clippings, rotting logs, stones, etc. They occasionally make their way indoors, feeding on spiders, flies, and other insects. When a centipede is found in the house, it is usually in a basement or bathroom.


These tiny arachnids range from rusty brown to dark red in color and are easily identified by their 2 long front legs. They are completely harmless and do not bite or sting, infest stored products or  harm plants. Clover mites can be an annoyance due to their large numbers. Clover mites only reproduce outdoors, therefore each clover mite found indoors came in from the outside. They feed on plant saps and are especially numerous in healthy, well-fertilized lawns. Crushing these pests can result in a dark brown or red stain.


The beetles are typically shiny black in color and have an elongated, somewhat-flattened body. Ground beetles are terrestrial and are typically found on the ground, harboring beneath stones, concrete slabs and other similar ground coverings during the day time.  Ground beetles can enter structures by crawling under door openings or flying through open doors and windows.


Field crickets are usually black in color, but can also be brownish-yellow to yellow. They tend to live outdoors around woodpiles, under mulch, plant beds and in other moist environments. Their presence is often announced by the males loud chirping, which can be heard both day and night. Field crickets can cause extensive damage to crops such as alfalfa, wheat, oats, rye, tomatoes, beans, etc. Besides crops, they will also feed on other insects and crickets.


Grand Daddy Longlegs have compact, oval bodies with 4 pairs of legs, the second pair being the longest. Females deposit their eggs in the ground, under stones, or in crevices of of wood. Daddy Longlegs feed on insects and spiders.


The house centipede is a long, flattened arthropod with a grayish-yellow body, 3 dark lines running lengthwise down the segmented body and long, slender legs. There are 15 pairs of legs with a pair on each segment. House centipedes prefer damp places such as basements, bathrooms, closets, underneath houses and beneath firewood. Their diet is small insects, spiders and insect larvae but are considered pests instead of beneficial. The house centipede can bite but is harmless to people.


Adult Japanese beetles are about 1/2 inch long, metallic green in color with copper/brown wing covers. They emerge from the ground and start feeding on plants in June. They feed in groups, devouring leaves, flowers and overripe or wounded fruit, starting at the top of the plant and working downward. Plants likely to be attacked include: Roses, Rose-of-Sharon, American Elm, English Elm, Mountain Ash, Gray Birch, Norway Maple and Japanese Maple.


Lady bugs—also known as lady beetles or ladybird beetles—are a beneficial insect and can eat as many as 5,000 aphids in its lifetime. Adult lady bugs have an oval shaped body that can be yellow, red, orange, black or pink in color and is usually marked with distinct spots.  They omit an odorous, noxious fluid when disturbed.  Some species become a nuisance as they try to stay in structures over winter.  They enter through cracks and crevices, gaps in siding and soffits, in attics, etc. and cluster together by the hundreds and thousands.


Millipedes are worm-like and are usually black or brown in color, but some species may have red and orange mottled patterns. Commonly called “thousand-leggers,” the millipede can have anywhere from 30–90+ pairs of legs. They are scavengers and feed on decaying organic matter. As scavangers, they are usually found under trash, mulch, leaf litter, etc. Millipedes are occasionally be found indoors in basements, cellars, etc. but usually die within a couple of days due to the lack of moisture and food.



The pillbug is gray in color and gets the nickname “roly-poly” because they roll up tightly into a ball when disturbed. The pillbug has 7 pairs of visible legs. They need moisture to survive so usually remain hidden under objects to prevent water loss. They may be found under leaf piles, mulch, rocks, trash, grass clippings, and other decaying vegetation. Pillbugs may occasionally make their way indoors on the ground level, indication a large population outdoors, but they don’t survive indoors very long due to the drier environment.


Slugs have a soft body that lacks segmentation, with one pair of conspicuous upper tentacles usually bearing eyes near the tip. Color varies from a dull brown to gray.


Springtails are usually whitish or gray in color and get their names from their ability to jump or “spring” 3–4.” They are a nuisance pest, attracted to areas of high moisture. They live in the soil and can number up to 50,000 per cubic foot. They may enter homes when it becomes too dry to survive outside. The springtail enters the home through screens, around doors, on potted plants, etc. They feed on fungi, algae, lichens, decaying vegetation, etc. When an infestation is indoors, they will be found in bathrooms, kitchens, basements, crawlspaces, and other damp areas. Outdoors, they may be found under mulch, leaf litter, firewood and other high moisture areas.


There are many different species of weevils. They have a very hard shelled oval-shaped body with a head that prolongs into a snout. Some species enter buildings in the fall to overwinter, while others enter in the spring to avoid unfavorable weather conditions. Positive species identification usually requires an expert. Some species are the Black Vine Weevil, which feeds on a variety of plants, the Asiatic Oak Weevil that feeds on woody plants, the Imported Longhorn Weevil, the Strawberry Root Weevil, and the Tulip Tree Weevil.