Pest library
Common pests in Wisconsin homes
Profiles of 22 pests that turn up in Wisconsin, grouped by type. Each one covers what it is, what it does, and how treatment works.
Wisconsin homeowners deal with a wide range of pests, and the mix shifts hard with the season. Mice push into heated homes through the long winter. Deer ticks carrying Lyme disease are active from spring through fall in wooded country. Asian lady beetles, box elder bugs, and cluster flies mass on warm walls and force their way indoors every autumn. Use the profiles below to figure out what you have, then get connected with a licensed exterminator in your area. If you want pricing first, the cost guide breaks down real Wisconsin ranges, and the services pages explain how each type of treatment works.
Rodents
2 profiles
House Mouse
The most common rodent in homes year-round. Small, fast, and capable of squeezing through a gap the width of a pencil, house mice nest inside walls and breed quickly.
Read moreNorway Rat
The large, burrowing rat found near foundations, dumpsters, and sewer lines. Norway rats cause serious structural damage and carry diseases that pose real health risks.
Read moreOccasional Invaders
4 profiles
Box Elder Bug
A flat black bug with orange-red markings that piles onto sun-warmed walls in fall, then shows up inside all winter. Harmless but a real nuisance.
Read moreBrown Marmorated Stink Bug
An invasive shield-shaped bug that enters homes by the hundreds each fall and releases a foul odor when disturbed. Harmless to people, serious to crops.
Read moreCamel Cricket
A large humpbacked cricket with no wings and very long legs that thrives in damp basements and crawl spaces. Startling but harmless.
Read moreMulticolored Asian Lady Beetle
The ladybug-looking beetle that invades homes by the hundreds each fall. It bites lightly, stains surfaces, and smells bad when disturbed.
Read moreTicks
2 profiles
American Dog Tick
A large brown-and-white tick found in grassy and brushy areas. It is the primary vector of Rocky Mountain spotted fever in the eastern United States.
Read moreDeer Tick
A small dark tick that carries Lyme disease. The nymph stage is the size of a poppy seed and accounts for most human infections in the Upper Midwest and Mid-Atlantic.
Read moreAnts
2 profiles
Carpenter Ant
A large black ant that excavates wood to nest. It does not eat the wood, but a long-established colony can cause real structural damage.
Read morePavement Ant
A small dark ant that nests under sidewalks and slabs, trails indoors for food, and throws up fine soil at crack edges along driveways and foundations.
Read moreCockroaches
2 profiles
American Cockroach
The largest common house cockroach, reddish brown and nearly two inches long, mostly found in basements, drains, and commercial buildings.
Read moreGerman Cockroach
The small light-brown roach behind most kitchen infestations. It breeds fast, hides in tight warm spots, and rarely clears up on its own.
Read moreSpiders
2 profiles
Common House Spider
The small, tan-to-brown spider responsible for most cobwebs in homes and garages, harmless to people, and effectively controlled through web removal and basic exclusion.
Read moreWolf Spider
A large, fast-moving ground spider that hunts without a web and is harmless to people, often alarming homeowners by its size and speed alone.
Read moreFlies
3 profiles
Cluster Fly
Large sluggish flies that spend the winter clustered in attics and wall voids, emerging on warm days to gather at windows in large numbers.
Read moreDrain Fly
Small fuzzy flies that breed in the organic sludge inside drains and rarely go away until that sludge is physically removed.
Read moreFruit Fly
Tiny tan flies drawn to overripe fruit and fermenting liquids, capable of going from egg to adult in about a week under warm conditions.
Read moreNot sure what you are dealing with?
Describe what you are seeing and a licensed Wisconsin operator will help identify it and quote the fix.