The short version
Madison rodent control works best when exclusion comes first. UW-Madison Extension advises blocking every opening over 1/4 inch for mice and over 1/2 inch for rats, across a band 36 inches above and below grade, then trapping: at least a dozen traps in a house, three to ten feet apart for mice. Most activity starts in fall as Madison heads toward 11F lows.
- Around Madison, mice and Norway rats move inside as fall temperatures drop and stay all winter.
- Use 1/2 inch hardware cloth for rats and 24-gauge 1/4 inch mesh for mice.
- Rodent-proof the foundation from 36 inches below grade to 36 inches above it.
- Expect rats to keep testing fresh repairs for about two weeks.
- A dozen traps is the minimum for a house; mouse traps work best about three feet apart.
This is for Madison homeowners who heard the first scratching in the walls this fall, renters near campus finding droppings in a kitchen drawer, landlords preparing units between leases, and small business owners who need a rodent plan that holds up. It also helps anyone comparing quotes and trying to tell a thorough exclusion job from a quick bait drop.
What to look for
Three rodents matter in Madison. House mice live inside walls, cabinets and insulation and stay close to food. Norway rats are larger burrowing rats that work along foundations, sewers and yards. Deer mice, with white bellies and two-tone tails, nest in garages, sheds and cabins and can carry hantavirus. The Wisconsin calendar sets the pace. Summers reach about 82F, and rodents breed outdoors through the warm months. UW-Madison Extension notes rodents move indoors as Wisconsin temperatures drop in fall. With winter lows near 11F, they have every reason to stay put until spring. Madison's wet, mild summers help populations grow. The city averages about 72% humidity and 35 inches of rain a year, and its location on an isthmus between lakes means plenty of damp soil and shoreline. Norway rats burrow in that soil and follow the foundation line looking for openings. That is why UW-Madison Extension treats exclusion as the core of rodent management. If gaps stay open, new rodents keep replacing the ones you trap.
- 1Small droppings along kitchen baseboards or in the back of the silverware drawer.
- 2Burrow holes near the foundation, under steps or beside the garage slab.
- 3Gnaw marks on wood or soft materials along the bottom of basement walls.
- 4Rustling or scratching in walls and ceilings during the first cold weeks of fall.
- 5Shredded paper or insulation tucked into a box, drawer or wall cavity.
- 6Rub marks along the foundation or basement walls where rats travel.
- 7Chewed bags of food, seed or pet food in the pantry or garage.
Why it’s worth acting soon
- Mice that move in during fall can breed through the whole Madison winter.
- Rats gnaw at foundations, wiring and pipes, and damage grows with time.
- Droppings and urine build up in insulation and stored items.
- Rental units can pass problems to neighbors through shared walls.
- Deer mouse droppings in garages and sheds raise exposure risk when you clean.
36 inches above and below gradeFoundation band to rodent-proof against Norway ratsUW-Madison Extension Treatment options and typical costs
Foundation band exclusion
Quoted after inspection
Sealing every opening in a band from 36 inches below grade to 36 inches above it, where Norway rats probe. Openings over 1/2 inch get hardware cloth sized for rats; openings over 1/4 inch get 24-gauge 1/4 inch mesh for mice. UW-Madison Extension treats this as the first and most important step.
- Time
- One to three days
- Best for
- Homes with Norway rats or repeat fall mouse entry
Interior trapping program
Quoted after inspection
Snap traps along walls and runways: at least a dozen in a typical house, spaced no more than 10 feet apart for mice, ideally about 3 feet. Rat traps go at least 20 feet apart. Traps that catch nothing in seven days get moved.
- Time
- Two to four weeks
- Best for
- Active mice or rats inside
Exterior rat service
Quoted after inspection
Locked bait stations and traps along the foundation, garage and yard, plus burrow treatment. Rats may keep testing new exclusion for about two weeks, so exterior monitoring during that period helps catch them before they find a weak spot.
- Time
- Monthly service
- Best for
- Norway rat burrows and outdoor activity
Cleanup and decontamination
Quoted after inspection
Removing droppings, nests and contaminated insulation using CDC cleanup steps. Important in garages, sheds and cabins where deer mice may be present.
- Time
- One to two days
- Best for
- Heavy contamination or deer mouse activity
Prices are typical published ranges. Ask what’s included before you compare quotes.
Crawl spaces are where rats and mice get comfortable. Vent screens, the sill plate and any gap around pipes are worth a careful look.The 36-inch band: rodent-proofing a Madison foundation.
A quote that only mentions caulking at ground level may miss the openings rats use most. If you hire a provider, ask how they handle below-grade sealing. Smaller gaps over 1/4 inch need 24-gauge 1/4 inch mesh for mice. Openings over 1/2 inch need hardware cloth sized for rats. Proofing that band means checking where utility lines enter, looking for cracks in block or poured walls, and sealing around window wells and basement doors. A gap a foot below the soil line, around a pipe or at a crack in the foundation, can be their main entry. Around Madison, damp soil near the lakes and along yards is easy for rats to dig. UW-Madison Extension recommends blocking all openings from 36 inches below grade to 36 inches above it, because rats work the foundation line and dig down to find a way in. Norway rats do not stop there. Most homeowners seal what they can see at ground level.
What happens in the two weeks after sealing.
For Madison homeowners, the practical step is to ask your provider: how many follow-up visits are included in the first two weeks, and what happens if rats get through? UW-Madison Extension also advises moving traps that catch nothing in seven days. Any rodent trapped inside after sealing needs to be removed. Inside, keep traps set. Traps or stations outside the sealed areas can catch rats while they test the work. A good plan includes checking the sealed areas during those two weeks and fixing anything rats have damaged. That is why follow-up matters. Weak spots, like loose edges or foam used alone, often fail. During that time, rats that lived inside or used the old openings will chew, scratch and dig at the new mesh and sealant. UW-Madison Extension notes rats may keep trying to break through fresh exclusion work for about two weeks. Rodent proofing is not finished the day it is installed.
Dense shrubs against the house and a dripping hose bib give rodents cover and water. Trimming back and fixing drips makes the yard less inviting.Trap spacing: mice versus rats.
Check traps daily and handle dead rodents with gloves. Keep traps away from children and pets, or use covered trap boxes. Rodents may be using a different route. Move traps that catch nothing in seven days. In warehouses, 50 to 100 is not excessive. At minimum, a private home needs about a dozen traps. Rats may avoid new traps for a few days, so leaving traps unset with bait for a short time can help. Rat traps should be at least 20 feet apart, placed along runways near walls and burrows. Rats travel farther and are more cautious. Put them along walls, behind appliances, in cabinets and along basement sills. UW-Madison Extension recommends placing mouse traps no more than 10 feet apart, and about 3 feet apart is better. Mice stay close to their nests. Trap placement for mice and rats is different, and getting it right in a Madison home saves time.
Rentals near campus: preparing units between leases.
In multi-unit buildings, mice move between units, so building-wide sealing and trapping usually work better than single-unit fixes. Tenants can help by keeping food sealed, taking out trash often and reporting signs in writing. Since rodents move indoors as Wisconsin temperatures drop, preparing units before fall is ideal. Timing matters. Set traps in empty units and check them before the new tenant moves in. Seal gaps over 1/4 inch with 24-gauge mesh and sealant. Check under sinks, behind stoves and refrigerators, and around radiators and pipes. Landlords can reduce problems by inspecting units between leases. Gaps around pipes, under sinks and behind appliances may also go unnoticed until a new tenant reports droppings. When tenants move out, food left in cabinets, trash left behind, and furniture moved around can attract mice. Rentals near UW-Madison can change hands every year, and that turnover creates openings for mice.
Deer mice in garages, sheds and cabins.
If you open a lake cabin or seasonal property in spring, assume mice may have used it over winter and follow these steps before moving in. Never sweep or vacuum dry droppings. After five minutes, lift it all with paper towels and seal it in a bag. Mix 1.5 cups of bleach into a gallon of water and wet every dropping and nest until soaked. Wear rubber gloves. Before cleaning a space with droppings, open doors and windows and let it air out for 30 minutes. Still, cleanup should be done carefully. The CDC has recorded 890 cases nationally since 1993, mostly in the West, and Wisconsin did not appear in the 2025 provisional count. Hantavirus is rare. In and around Madison, they often show up in garages, sheds, cabins and storage areas. They have white bellies and feet and a sharply two-tone tail. Deer mice live in Wisconsin and are the species tied to hantavirus.
What affects the price
- How many openings exist in the 36-inch foundation band.
- Whether rats are present, requiring heavier hardware cloth and exterior service.
- Basement and crawlspace access.
- Number of rental units or rooms needing traps.
- Garages, sheds and outbuildings to include.
- Follow-up visits during the two weeks after exclusion.
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What's your biggest concern about rodents?
When to call for help
Call a pro if you see rats or burrows, keep catching mice after two weeks, or find droppings in several rooms. Finding and sealing every opening in the foundation band takes time and tools, and rats are persistent. UW-Madison Extension notes they may keep trying to break through new rodent proofing for about two weeks, so follow-up matters. Landlords preparing Madison rental units for new tenants often benefit from a professional inspection, since mice can move between units and shared walls hide entry points.
What you can do yourself
For a few mice, DIY works if you are thorough. Set at least a dozen snap traps along walls, ideally three feet apart, and move any that catch nothing after a week. Seal gaps over 1/4 inch with 24-gauge 1/4 inch hardware cloth or mesh, held with sealant. Rats are tougher. They need openings over 1/2 inch sealed with heavier hardware cloth, and proofing should cover the foundation from 36 inches below grade to 36 inches above. That often means digging along the foundation, which is real work. Rats also test fresh repairs for about two weeks, so weak spots show up fast. A provider can do the foundation band work, place exterior stations safely and return during the testing period. For Madison landlords and owners of older homes, that inspection often finds gaps a DIY effort would miss.
Rodents in Madison
Madison is Wisconsin's capital, founded in 1836 on an isthmus between lakes, and home to UW-Madison. About 273,000 people live there. The isthmus and lakeshore mean damp soil and water close to many neighborhoods, which suits Norway rats that burrow along foundations. The climate is humid continental: summer highs near 82F, winter lows around 11F, 72% humidity and roughly 35 inches of rain a year, at an elevation of about 863 feet. That gives rodents a productive summer outdoors and a strong push indoors in fall. Where rental units near campus change hands each year, gaps or food left behind can bring mice in. With median home values around $360,000, homeowners often want exclusion done right the first time. UW-Madison Extension's applicator training, which treats exclusion as the core of rodent control, is local expertise that applies directly here.
Local research
Rodents in Madison, WI: what the public record shows
Before you compare quotes, it helps to know which rodents actually live in Wisconsin, when they are busiest around Madison, and what the state figures look like. Everything below links to the agency or university page it came from.
Rodent species recorded in Wisconsin
- House mouse (Mus musculus) — Enters at 1/4 inch; 5-10 litters per year; eats about 200 small meals a night.
- Norway rat (Rattus norvegicus) — Burrowing rat of basements, sewers and ground floors; tail shorter than head plus body.
- Deer mouse (Peromyscus maniculatus) — Primary U.S. hantavirus carrier; lives throughout Washington and the interior West.
When rodents are busiest around Madison
Rodents move indoors as Wisconsin temperatures drop in fall.
UW-Madison Extension's applicator training treats exclusion as the core of rodent management, with trapping second.
For context, nationally
- 1/4 inch (the width of a pencil) — Smallest gap a mouse can enter. CDC
- 890; 35% fatal; 94% west of the Mississippi — Hantavirus cases reported since 1993 (through 2023). CDC
Sources: University of Wisconsin-Madison Division of Extension; CDC; Pest Notes: House Mouse; Pest Notes: Rats; Hantavirus. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep rodents away
- Seal foundation gaps in late summer, before temperatures drop in fall.
- Use 24-gauge 1/4 inch mesh for mouse gaps and 1/2 inch hardware cloth for rat openings.
- Check the foundation 36 inches above and below grade for cracks and holes.
- Keep firewood, lumber and debris away from the foundation.
- Store food and pet food in hard, sealed containers.
- Install door sweeps on garage and basement doors.
- Keep trash in lidded cans and clean up around them.
- Set a few traps in the garage and basement as an early warning each fall.
Before you call, sketch where you have seen droppings or heard noise and measure any gaps you found. It makes the first visit faster and the quotes comparable.Did you know?
UW-Madison Extension says 50 to 100 traps is not excessive for a warehouse.
Norway rats can wean 20 or more young a year from four to six litters.
The 2025 provisional U.S. hantavirus count included one case in Illinois, one of only three east of the Mississippi.
Questions people ask
When do rodents move inside in Madison?
Rodents usually move into Madison homes from about September through November, as temperatures drop. UW-Madison Extension describes this fall shift across Wisconsin. With winter lows near 11F, mice and rats that get inside stay until spring, so late summer is the time to seal.
What size mesh keeps mice and rats out?
UW-Madison Extension says mice get through openings over 1/4 inch and rats through openings over 1/2 inch. Use 24-gauge 1/4 inch hardware cloth for mice and 1/2 inch hardware cloth for rats, fastened securely and sealed around the edges so nothing can pry it loose.
How far apart should mouse traps be?
No more than 10 feet apart, and about 3 feet is better, according to UW-Madison Extension. Rat traps should be at least 20 feet apart. A dozen traps is the minimum for a house, and traps that catch nothing in seven days should be moved.
Why do rats keep coming back after sealing?
Rats may keep testing new rodent proofing for about two weeks, UW-Madison Extension notes. They chew and dig at fresh repairs looking for a weak spot. That is why follow-up visits and exterior monitoring during those two weeks matter for Madison homes.
Do Madison rentals near campus get more mice?
Rentals with frequent turnover can see more mice if food is left behind or gaps go unrepaired between tenants. Around Madison, landlords can reduce problems by sealing gaps and setting traps before new leases start, especially ahead of fall. Tenants should report signs in writing.
Is hantavirus a concern in Wisconsin?
It is rare. Wisconsin was not among the states in the CDC's 2025 provisional hantavirus count. Deer mice do live here, so clean garages, sheds and cabins carefully: ventilate 30 minutes, wear gloves, soak droppings with bleach solution for five minutes, and never sweep.
What is the 36-inch rule for rats?
UW-Madison Extension recommends blocking all openings from 36 inches below grade to 36 inches above it. Norway rats work along the foundation line and dig down, so sealing only at ground level leaves gaps they can use. In damp Madison soil, that digging is easy.
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The facts in this article come from the public sources listed above. Every home is different, so ask the company you talk to about pricing and what’s included. Published by Rodent Exterminator · Updated October 11, 2026 · How we write these guides