Common House Bugs: 30 Types and What to Do
Common House Bugs are one of the most common identification questions we get. Here are 30 you are likely to see.
Quick list
- Arizona Bark Scorpion
- Cat Flea
- Head Louse
- Paper Wasp
- Wolf Spider
- Asian Lady Beetle
- Blow Fly
- Boxelder Bug
- Brown Marmorated Stink Bug
- Carpenter Ant
- Carpenter Bee
- Clover Mite
- Drywood Termite
- Eastern Subterranean Termite
- Fungus Gnat
- Hobo Spider
- House Fly
- June Bug
- Smokybrown Cockroach
- Southern House Spider
- Varied Carpet Beetle
- Western Conifer Seed Bug
- Bold Jumping Spider
- Booklouse
- Common House Spider
- Crane Fly
- House Cricket
- Mud Dauber
- Spotted Orbweaver
- Springtail
How to narrow it down
Narrow it down with three quick checks. Count the legs: insects have six, spiders and ticks have eight, and centipedes and millipedes have many more. Check for wings, even folded ones. Then compare size against a coin: a US penny is 19 mm across. Our bug identifier tool does this filtering for you.
The 30 bugs
Arizona Bark Scorpion
Arizona Bark ScorpionCentruroides sculpturatusA slender, light tan scorpion of the desert Southwest and the most venomous scorpion in North America. It climbs walls and ceilings and often hides in shoes, bedding and clothing.
Tell-tale sign: Thin, light yellowish-tan body and slender pincers. Risk: Bark scorpion stings cause severe pain and numbness and can be dangerous for young children and older adults; call Poison Control at 1-800-222-1222 after a sting.
Cat Flea
Cat FleaCtenocephalides felisThe most common flea on both cats and dogs, a tiny, flattened, dark insect that jumps huge distances. Eggs drop off pets into carpets and bedding.
Tell-tale sign: Tiny, reddish-brown to black body flattened side to side. Risk: Flea bites itch, can cause allergic dermatitis in pets, and fleas can pass tapeworms.
Head Louse
Head LousePediculus humanus capitisA tiny, wingless insect that lives only on the human scalp and feeds on blood. Its eggs, called nits, are glued firmly to hair near the scalp.
Tell-tale sign: Sesame-seed-size tan or grayish insect on hair. Risk: Head lice are itchy but don't spread disease; they spread mainly by head-to-head contact.
Paper Wasp
Paper WaspPolistes spp.A slender wasp with long, dangling legs that builds open, umbrella-shaped paper nests under eaves, railings and grills. It hunts caterpillars to feed its young.
Tell-tale sign: Long, thin body with a narrow waist. Risk: Paper wasps are less aggressive than yellowjackets but will sting to defend their nest.
Wolf Spider
Wolf SpiderLycosidae familyA large, hairy, fast-running spider that hunts on the ground instead of building webs. Females carry their egg sacs and then their spiderlings on their backs.
Tell-tale sign: Hairy brown or gray body with dark stripes. Risk: Wolf spiders can bite if handled, causing pain and swelling like a bee sting, but they're not dangerous.
Asian Lady Beetle
Asian Lady BeetleHarmonia axyridisAn imported lady beetle that ranges from pale orange to red with anywhere from zero to 19 spots. In fall it gathers in large numbers on sunny walls and slips indoors to spend the winter.
Tell-tale sign: Orange to red dome-shaped body with a variable number of spots. Risk: They can give a mild pinch and release a yellow, smelly fluid that stains, but they carry no disease.
Blow Fly
Blow FlyLucilia sericataA shiny, metallic green or blue fly that lays eggs on dead animals, meat and garbage. A sudden swarm indoors often signals a dead mouse or bird in a wall or attic.
Tell-tale sign: Metallic green, blue or bronze body. Risk: Blow flies don't bite but can carry bacteria from rotting material.
Boxelder Bug
Boxelder BugBoisea trivittataA black bug with red-orange lines on its back that feeds on the seeds of boxelder and maple trees. Large groups sun themselves on warm walls in fall before crawling inside.
Tell-tale sign: Black body with three red lines on the thorax. Risk: Boxelder bugs rarely bite and are harmless, but their droppings can stain curtains.
Brown Marmorated Stink Bug
Brown Marmorated Stink BugHalyomorpha halysA shield-shaped, mottled brown bug that invades homes in fall to overwinter and feeds on fruit and vegetables in summer. It releases a sharp odor when disturbed or crushed.
Tell-tale sign: Shield-shaped, marbled brown body. Risk: Stink bugs don't bite or sting people; they are a household and crop nuisance.
Carpenter Ant
Carpenter AntCamponotus pennsylvanicusA large black ant that nests in moist or damaged wood, including window frames, decks and wall voids. It doesn't eat wood but excavates smooth galleries and pushes out sawdust-like debris.
Tell-tale sign: Large ant with an evenly rounded, single-arch thorax. Risk: Carpenter ants can deliver a painful bite and weaken wood over time, but they do not carry disease.
Carpenter Bee
Carpenter BeeXylocopa virginicaA large bee that bores perfectly round holes into bare wood on decks, eaves and fences. Males hover aggressively near nests but cannot sting.
Tell-tale sign: Shiny, hairless black abdomen. Risk: Females can sting but rarely do; repeated nesting weakens wood and attracts woodpeckers.
Clover Mite
Clover MiteBryobia praetiosaA tiny, red-brown mite that crawls by the thousands onto sunny walls and windowsills in spring and fall. Crushed mites leave red stains.
Tell-tale sign: Pinhead-size red to brown dots moving on walls. Risk: Clover mites don't bite people or damage homes; they're a staining nuisance.
Drywood Termite
Drywood TermiteIncisitermes minorA termite that lives entirely inside dry wood such as furniture, attics and window frames, with no soil contact. It is most common in coastal California, the Southwest and Florida.
Tell-tale sign: Small piles of hard, six-sided fecal pellets. Risk: Drywood termites don't bite people; long-term colonies weaken furniture and framing.
Eastern Subterranean Termite
Eastern Subterranean TermiteReticulitermes flavipesThe most widespread termite in North America, living in underground colonies and reaching wood through mud tubes. Dark, winged swarmers emerge indoors on warm spring days.
Tell-tale sign: Creamy white, soft-bodied workers in soil and wood. Risk: Termites don't bite people but can cause costly structural damage over time.
Fungus Gnat
Fungus GnatBradysia spp.A tiny, dark, mosquito-like fly that hovers around houseplants and windows. Its larvae live in moist potting soil and feed on fungi and roots.
Tell-tale sign: Delicate dark body with long legs and antennae. Risk: Fungus gnats don't bite; larvae can damage seedlings and young roots.
Hobo Spider
Hobo SpiderEratigena agrestisA brown funnel-web spider of the Pacific Northwest that builds sheet webs with a funnel retreat in window wells, basements and woodpiles. Males wander indoors in late summer and fall.
Tell-tale sign: Brown body with a herringbone pattern on the abdomen. Risk: Hobo spiders were once blamed for dangerous bites, but current research does not show they cause necrotic wounds.
House Fly
House FlyMusca domesticaThe most common fly in homes, a dull gray fly with four dark stripes on its thorax. It breeds in garbage, manure and rotting food and lands on nearly everything.
Tell-tale sign: Four dark lengthwise stripes on a gray thorax. Risk: House flies don't bite, but they can carry bacteria that cause food poisoning.
June Bug
June BugPhyllophaga spp.A heavy, reddish-brown beetle that crashes into screens and porch lights on late-spring nights. Its C-shaped white grubs live in soil and chew grass roots.
Tell-tale sign: Chunky, shiny reddish-brown to dark brown body. Risk: June bugs are harmless to people; they do not bite or sting.
Smokybrown Cockroach
Smokybrown CockroachPeriplaneta fuliginosaA large, uniformly dark mahogany cockroach common in the humid Southeast. It lives outdoors in tree holes, mulch and gutters and flies toward lights at night.
Tell-tale sign: Shiny, uniformly dark brown body with no markings. Risk: Smokybrown cockroaches can carry bacteria indoors from mulch and garbage.
Southern House Spider
Southern House SpiderKukulcania hibernalisA velvety, dark gray to brown spider of the southern US whose males look like brown recluses. Females build radiating, lint-like webs around cracks in walls and windows.
Tell-tale sign: Velvety, uniformly dark females with a small head. Risk: Southern house spiders rarely bite and are not medically significant.
Varied Carpet Beetle
Varied Carpet BeetleAnthrenus verbasciA tiny, round beetle mottled with white, brown and yellow scales. The fuzzy, banded larvae chew holes in wool, silk, feathers, leather and stored animal products.
Tell-tale sign: Very small, round beetle with a mottled scale pattern. Risk: Carpet beetles don't bite, but larval hairs can cause itchy skin rashes in some people.
Western Conifer Seed Bug
Western Conifer Seed BugLeptoglossus occidentalisA long, brown bug with flattened, leaf-like expansions on its hind legs. It feeds on pine cones in summer and wanders indoors in fall, buzzing loudly when it flies.
Tell-tale sign: Leaf-shaped flat widenings on the hind legs. Risk: Western conifer seed bugs don't bite or sting; they may release a pine-like odor.
Bold Jumping Spider
Bold Jumping SpiderPhidippus audaxA compact, fuzzy black spider with white spots and iridescent green mouthparts. It stalks prey with excellent eyesight and leaps several times its body length.
Tell-tale sign: Two very large, front-facing eyes. Risk: Jumping spiders are shy and harmless; a rare bite feels like a mild pinch.
Booklouse
BooklouseLiposcelis spp.A tiny, soft, pale insect that feeds on microscopic mold growing on paper, cardboard and stored food. It thrives in humid rooms and new construction.
Tell-tale sign: Very small, pale, wingless body. Risk: Booklice don't bite and aren't true lice; they indicate high humidity and mold.
Common House Spider
Common House SpiderParasteatoda tepidariorumA small, brownish spider that builds tangled cobwebs in corners, windows and basements. It is the web-builder most often seen inside North American homes.
Tell-tale sign: Round, mottled brown abdomen with chevron markings. Risk: Common house spiders are harmless and help catch flies and other indoor pests.
Crane Fly
Crane FlyTipula spp.A huge, fragile, long-legged fly often mistaken for a giant mosquito. Adults barely feed, and the larvae, called leatherjackets, eat grass roots.
Tell-tale sign: Extremely long, thin legs that detach easily. Risk: Crane flies cannot bite or sting and do not eat mosquitoes, despite the nickname mosquito hawk.
House Cricket
House CricketAcheta domesticusA light yellowish-brown cricket with three dark bands on its head that chirps loudly at night. It wanders indoors in fall and can chew fabric and paper.
Tell-tale sign: Yellowish-brown body with dark crossbands on the head. Risk: House crickets are harmless, though they can damage clothing and keep you awake.
Mud Dauber
Mud DauberSceliphron caementariumA solitary wasp with a thread-thin waist that builds tube-shaped mud nests on walls, ceilings and under porches. It stocks each nest with paralyzed spiders.
Tell-tale sign: Extremely long, thread-like waist. Risk: Mud daubers are non-aggressive and very rarely sting, even when handled.
Spotted Orbweaver
Spotted OrbweaverNeoscona cruciferaA round, hairy orb weaver that builds a new web each evening on porches, eaves and shrubs. By day it hides in a curled leaf or a nearby corner.
Tell-tale sign: Large, round, hairy abdomen, often reddish or orange. Risk: Spotted orbweavers are harmless and help control flying insects.
Springtail
SpringtailCollembola classA tiny, wingless hexapod that jumps using a tail-like spring folded under its body. Springtails swarm in damp soil, potted plants and around leaks.
Tell-tale sign: Pinhead-size gray, white or black body. Risk: Springtails don't bite or damage homes; large numbers usually point to a moisture problem.
Which ones should you worry about?
5 of the 30 bugs in this guide can bite or sting. The ones to take seriously are Arizona bark scorpion. The rest are harmless or simply a nuisance.
Frequently asked questions
What is the most common one?
Among the bugs in this guide, the Arizona bark scorpion and cat flea are the ones people ask about most.
Which of these are dangerous?
Arizona Bark Scorpion can be medically significant.
How can I identify a bug I found?
Use the free bug identifier tool: choose the number of legs, wings, main color, size and where you found it, and it will list the closest matches.