Bugs in the Basement or Garage: 25 Types and What to Do
Bugs in the Basement or Garage are one of the most common identification questions we get. Here are 25 you are likely to see.
Quick list
- Black Widow Spider
- Brown Recluse Spider
- Wolf Spider
- American Cockroach
- Carpenter Ant
- Drain Fly
- Earwig
- Eastern Subterranean Termite
- Hobo Spider
- House Centipede
- Larder Beetle
- Millipede
- Oriental Cockroach
- Pavement Ant
- Silverfish
- Southern House Spider
- Booklouse
- Camel Cricket
- Cellar Spider
- Common House Spider
- Ground Beetle
- Harvestman
- House Cricket
- Pill Bug
- 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 25 bugs
Black Widow Spider
Black Widow SpiderLatrodectus mactansA shiny black spider with a red hourglass on the underside of its round abdomen. It builds messy, tangled webs in woodpiles, sheds, meter boxes and outdoor furniture.
Tell-tale sign: Glossy black, globe-shaped abdomen. Risk: Females have venom that can cause severe muscle pain and cramps; seek medical care after a bite.
Brown Recluse Spider
Brown Recluse SpiderLoxosceles reclusaA tan to brown spider with a dark violin-shaped mark on its back and only six eyes. It hides in boxes, closets and unused clothing in the south-central US.
Tell-tale sign: Dark violin-shaped mark pointing toward the abdomen. Risk: Most bites are mild, but some cause a spreading wound that needs medical care.
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.
American Cockroach
American CockroachPeriplaneta americanaThe largest common house cockroach, a reddish-brown roach that lives in sewers, basements and steam tunnels. It can fly short distances in warm weather.
Tell-tale sign: Large reddish-brown body up to two inches long. Risk: American cockroaches can spread bacteria to food and trigger allergies and asthma.
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.
Drain Fly
Drain FlyClogmia albipunctataA small, fuzzy, moth-like fly that rests on bathroom walls near sinks, tubs and floor drains. Its larvae live in the slimy film inside drains.
Tell-tale sign: Fuzzy, gray, leaf-shaped wings held roof-like over the body. Risk: Drain flies don't bite and aren't known to spread disease in homes.
Earwig
EarwigForficula auriculariaA slender, reddish-brown insect with a pair of pincers on its tail. Earwigs hide under mulch and pots by day and chew seedlings, flowers and soft fruit at night.
Tell-tale sign: Forceps-like pincers at the end of the abdomen. Risk: Earwigs can pinch but are harmless, and they do not crawl into ears.
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.
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 Centipede
House CentipedeScutigera coleoptrataA fast, yellowish-gray centipede with 15 pairs of very long legs that races across floors and walls at night. It hunts silverfish, cockroaches and spiders.
Tell-tale sign: Fifteen pairs of long, banded legs. Risk: House centipedes rarely bite; a bite feels like a mild bee sting.
Larder Beetle
Larder BeetleDermestes lardariusA dark, oblong beetle with a pale yellowish band across the front half of its back. Its hairy larvae feed on dried meats, pet food, cheese and dead insects.
Tell-tale sign: Dark, oblong body with a light tan band across the wing covers. Risk: Larder beetles don't bite, but larvae can bore into wood and they contaminate food.
Millipede
MillipedeOxidus gracilisA slow-moving, cylindrical arthropod with two pairs of legs on most body segments. Millipedes eat decaying leaves and often migrate indoors after heavy rain.
Tell-tale sign: Rounded, segmented body with many short legs. Risk: Millipedes don't bite; some release a fluid that can stain or irritate skin.
Oriental Cockroach
Oriental CockroachBlatta orientalisA shiny, dark brown to black cockroach that prefers cool, damp places such as basements, drains and crawl spaces. Females have tiny wing pads, and neither sex can fly.
Tell-tale sign: Glossy black or very dark brown body. Risk: Oriental cockroaches feed on garbage and sewage and can spread bacteria to surfaces.
Pavement Ant
Pavement AntTetramorium immigransA dark brown ant that nests under sidewalks, driveways and slabs, pushing up small piles of sand. Colonies fight noisy battles on pavement in spring.
Tell-tale sign: Parallel grooves on the head and thorax. Risk: Pavement ants have a weak sting that rarely bothers people; they are mainly a nuisance.
Silverfish
SilverfishLepisma saccharinaA wingless, carrot-shaped insect covered in silvery scales that moves with a fish-like wiggle. It eats paper, glue, starches and fabrics in damp areas.
Tell-tale sign: Silvery-gray, teardrop-shaped, scaly body. Risk: Silverfish don't bite; they damage books, wallpaper and stored papers.
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.
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.
Camel Cricket
Camel CricketDiestrammena asynamoraA humpbacked, wingless cricket with very long legs and antennae that lives in basements, crawl spaces and garages. It jumps toward threats, which startles many people.
Tell-tale sign: Arched, humpbacked brown body. Risk: Camel crickets don't bite or spread disease; they point to damp conditions.
Cellar Spider
Cellar SpiderPholcus phalangioidesA pale, delicate spider with extremely long, thin legs that hangs upside down in loose webs in basements and ceiling corners. When disturbed, it vibrates rapidly in its web.
Tell-tale sign: Tiny, peanut-shaped body with very long, hair-thin legs. Risk: Cellar spiders are harmless to people; the myth that they are deadly but can't bite is false.
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.
Ground Beetle
Ground BeetleCarabidae familyA fast-running, shiny black beetle that hunts slugs, caterpillars and other insects at night. Ground beetles often wander into basements and garages from nearby mulch and leaf litter.
Tell-tale sign: Shiny black body, often with a metallic sheen. Risk: Ground beetles rarely bite and are beneficial predators; a few release a harmless, bad-smelling spray.
Harvestman
HarvestmanOpiliones orderOften called daddy longlegs, a long-legged arachnid with a single fused, oval body and no venom glands. It scavenges on dead insects, fungi and plant matter.
Tell-tale sign: One round body section instead of two. Risk: Harvestmen have no venom and no silk; they are completely harmless.
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.
Pill Bug
Pill BugArmadillidium vulgareA small land crustacean that rolls into a tight ball when disturbed, also called a roly-poly. It eats decaying plant matter in damp soil and mulch.
Tell-tale sign: Gray, armored, segmented body with seven pairs of legs. Risk: Pill bugs are harmless and only occasionally nibble seedlings.
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?
3 of the 25 bugs in this guide can bite or sting. The ones to take seriously are black widow spider and brown recluse spider. The rest are harmless or simply a nuisance.
Frequently asked questions
What is the most common one?
Among the bugs in this guide, the black widow spider and brown recluse spider are the ones people ask about most.
Which of these are dangerous?
Black Widow Spider and Brown Recluse Spider 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.