The short version
Rodent control in Missoula, Montana, is mostly about mice: house mice in kitchens and walls, and deer mice in garages, sheds and cabins. Montana has recorded 49 hantavirus cases since 1993, with 11 deaths, and deer mice are the carrier. Follow the state's sequence: seal up gaps of 1/4 inch, trap up with snap traps, and clean up wet, never by sweeping.
- Deer mice and house mice cause most rodent problems in Missoula.
- Montana has logged 49 hantavirus cases since 1993, 11 of them fatal.
- Deer mice carry hantavirus statewide; house mice do not.
- Opening sheds, cabins and gear storage in spring is the riskiest moment.
- Seal up, trap up, clean up, and never sweep or vacuum droppings.
This is for Missoula homeowners finding mice in kitchens and garages, people with sheds, cabins or gear rooms full of camping and ski equipment, students renting near the University of Montana, and anyone getting ready to clean out a closed building in spring. It also helps you decide which cleanup jobs to handle yourself and which to hand off.
What to look for
Montana's household rodent list includes the deer mouse, the white-footed mouse, the house mouse and the Norway rat. Around Missoula, mice are the main story. House mice live in walls, cabinets and basements and are a classic fall nuisance. Deer mice are native field mice that move into unoccupied buildings, garages, sheds and cabins, and they are the hantavirus carrier across Montana. The white-footed mouse plays that role in eastern Montana. Missoula's climate shapes the cycle. Summers reach about 86F, but at roughly 3,209 feet with only about 15 inches of precipitation a year and humidity near 62 percent, the air is dry and nights cool quickly. Winter lows average about 18F, which pushes mice indoors from September through November. They stay all winter. Dry air matters for cleanup. Droppings and nests dry out and crumble, and stirring that dust is how people inhale hantavirus. Montana health officials report that exposure usually happens while cleaning cabins, sheds and outbuildings. So the most important part of rodent control here is not catching the mice. It is how you clean up after them.
- 1Small dark droppings in garage corners, gear bins or a cabin pantry.
- 2Nests of shredded fabric, paper or insulation in sleeping bags, boxes or a camper.
- 3Seeds or chewed food stashed in boots, drawers or an engine compartment.
- 4Scratching in walls or ceilings as nights cool in fall.
- 5Chewed holes in bags of birdseed, dog food or grass seed.
- 6A musty smell when you open a shed or cabin after winter.
- 7Mice with white bellies and bicolored tails, the look of a deer mouse.
Why it’s worth acting soon
- Deer mouse droppings build up in closed spaces and raise hantavirus exposure during cleanup.
- Montana health officials report 11 deaths among 49 hantavirus cases since 1993.
- House mice breed through the winter indoors, so a few in fall become many by spring.
- Mice chew wiring in vehicles, campers and walls, an expensive repair.
- Nesting in sleeping bags, tents and gear can ruin equipment.
49, including 11 deathsMontana hantavirus cases since 1993Montana DPHHS 52 percentWestern homeowners who reported a rodent encounter in their lifetime (NPMA/Harris Poll, September 2022; self-reported)NPMA / Harris Poll (2022) Treatment options and typical costs
Seal up
Quoted after inspection
Closing every gap of 1/4 inch or more around garage doors, utility lines, foundation vents, decks and rooflines with steel wool, copper mesh, hardware cloth and metal flashing. This is step one of the sequence Montana health officials follow. For Missoula homes, finishing it by late August beats the fall rush indoors.
- Time
- Depends on how many openings the inspection finds
- Best for
- Homes, garages and sheds with returning mice
Trap up
Quoted after inspection
Snap traps set along walls in garages, kitchens, basements and outbuildings, checked daily or on a schedule. Snap traps are preferred where deer mice are possible, since live traps leave you handling a live mouse. Ask the provider how traps are checked and how carcasses are handled.
- Time
- Until catches stop; ask how many checks are included
- Best for
- Active indoor activity
Clean up
Quoted after inspection
Ventilating, soaking droppings and nests with disinfectant, and removing contaminated material with gloves and respiratory protection. This is the step where hantavirus exposure happens, so Montana officials stress never sweeping or vacuuming. Ask what protective gear the crew uses and how waste is bagged.
- Time
- Depends on how much soiled material has to come out
- Best for
- Sheds, cabins and garages with heavy droppings
Cabin and outbuilding service
Quoted after inspection
Sealing and cleanup for cabins, sheds and outbuildings that sit closed for months. Deer mice favor these buildings, and the first spring cleaning is the riskiest moment. Ask whether the provider can do a preseason cleanout before you open up.
- Time
- Depends on the building's size and condition
- Best for
- Seasonal cabins and rural outbuildings
Prices are typical published ranges. Ask what’s included before you compare quotes.
Bathroom vanities hide the same plumbing gaps as the kitchen. A quick look with a flashlight shows droppings or rub marks long before you see a mouse.What Montana's hantavirus record means for Missoula homes.
Exposure usually comes from ordinary chores, like cleaning a cabin, shed or outbuilding where deer mice have been living. For a Missoula household, that means the risk is less about mice in the kitchen and more about the first cleanup of a closed space. Deer mice settle into garages, sheds, campers and cabins, and their droppings dry out quickly in Montana's dry air. The response is careful cleanup: ventilate, soak, wait, wipe and bag. Low case numbers are a reason for care, not panic. Montana takes hantavirus seriously because its record is heavy for a state of its size. The Department of Public Health and Human Services reports 49 cases since 1993, with 11 deaths. A typical year brings zero to two cases, and six were reported from 2020 through 2025: four infections that did not progress to pulmonary syndrome and two that did. The patients are not who most people picture. The median age is 45, and cases have ranged from age 8 to 68.
Seal up, trap up, clean up: the Montana sequence.
Check them daily, wear gloves, and spray each mouse with disinfectant before bagging it. Clean up. Ventilate the space for 30 minutes. Soak droppings, urine and nests with bleach solution at 1.5 cups per gallon of water and wait 5 minutes. Wipe up with paper towels, bag everything, and disinfect surfaces. Never sweep or vacuum. Skipping the first step means trapping new mice indefinitely. Skipping the last step leaves the health risk behind. Doing all three, in order, is what keeps a Missoula home clear. Montana health officials follow the CDC's three-step sequence, and the order matters. Seal up. Close every gap of 1/4 inch or more around garage doors, utility lines, foundation vents, decks and rooflines. Use steel wool, copper mesh, hardware cloth and metal, not foam alone. For Missoula homes, aim to finish by late August, before mice push indoors. Trap up. Set snap traps along walls in garages, kitchens and outbuildings. Snap traps are preferred over live traps where deer mice are possible.
Fall is when rodents head indoors. Leaf piles against the foundation hide burrows and gaps, so clear them and walk the wall before the first cold snap.Gear rooms, garages and cabins in an outdoor town.
Cabins are the bigger concern. A cabin closed for months can hold a lot of droppings and nests, and the first spring cleaning is when Montana health officials see most exposures. Open windows and doors and wait 30 minutes before entering to clean. Wear gloves and, for heavy nesting, a respirator. Soak everything before you touch it. Before closing a cabin for winter, remove food, seal vents and gaps, add door sweeps and set snap traps so you can see what happened when you return. If you keep outdoor gear in Missoula, the tents, sleeping bags, skis, packs and camping stoves probably sit in a garage, basement or shed. Deer mice love that kind of storage. It is quiet, soft and often comes with crumbs. Store gear in sealed plastic bins with tight lids, off the floor if possible. Never store food in gear bins, including snacks left in pack pockets. Check gear for droppings before trips, and if you find any, clean it outside with disinfectant rather than shaking it out indoors.
When do mice move into Missoula homes?
December through February: winter lows average about 18F. Mice that got inside stay and keep breeding. Trap steadily and look for the gap that let them in. March through May: cabins, sheds and gear rooms get opened. Montana health officials say this is when hantavirus risk peaks, because people clean up winter's droppings. The pattern is simple: seal in summer, watch in fall, trap in winter, clean carefully in spring. Following it keeps both the house and the outbuildings under control. Mice in Missoula follow a predictable calendar shaped by cold nights and dry air. June through August: mice live outdoors, feeding in fields, gardens and forest edges. Summer highs near 86F and long days keep them busy outside. This is the best time to seal the house and garage. September through November: the main entry season. At about 3,209 feet, nights cool quickly, and mice begin probing garage doors, foundation vents and utility gaps. Set a few snap traps in the garage in September as an early warning.
Renters and students: rodent problems in Missoula rentals.
A lease that begins in late summer starts just before the fall entry season, when mice push indoors, so problems can start within weeks of moving in. Do not sweep up droppings in a shared garage, basement storage area or shed. Ask the landlord to arrange cleanup using the wet method, or follow it yourself carefully if the area is small. Landlords should treat rodent reports as a building issue: inspect and seal basements, laundry rooms and utility entries, trap in affected units at the same time, and use turnover periods for sealing work. If you rent in Missoula, especially near the University of Montana, report mouse signs early and in writing. Mice move between units through shared walls and pipe chases, so a problem rarely stays in one apartment. Take dated photos of droppings, gnaw marks and damage, and send them to your landlord or property manager by email so there is a record. Keep food in hard containers, take trash out often and do not leave pet food out overnight.
What affects the price
- The number of openings around garages, foundations, decks and rooflines.
- Sheds, cabins and outbuildings that need separate sealing and cleanup.
- Heavy deer mouse contamination that requires protective gear.
- Insulation that must be removed and replaced.
- Distance and access for rural cabins outside town.
- The number of follow-up visits included.
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What's your biggest concern about rodents?
When to call for help
Bring in a provider when you have to clean a shed, cabin, garage or crawlspace with heavy deer mouse signs, since that is where hantavirus exposure happens. Get help as well when mice keep returning after you seal and trap, when you cannot find entry points, or when nests are in insulation or walls. If you own a cabin outside Missoula, a preseason cleanout by someone with protective gear is worth considering. Ask any company how they protect their workers during cleanup, which openings they plan to seal, and how many follow-up visits are included.
What you can do yourself
Most house mouse problems in a Missoula home are manageable on your own. Seal gaps around pipes and doors with steel wool and caulk, replace the garage door seal, store seed and pet food in metal containers, and set snap traps along the walls. Check traps daily, wear gloves, and spray each dead mouse with disinfectant before bagging it. The risky part is cleanup in closed buildings. A shed, cabin, camper or gear room that sat closed all winter can hold months of deer mouse droppings and nests, and in dry air that material breaks into dust easily. Montana health officials follow the CDC method: ventilate, soak, wait, wipe, bag. It works if you follow it exactly, but large jobs in cramped spaces call for a respirator and are worth handing off. A provider also helps when you cannot find how mice are getting in, since gaps under decks and at rooflines are easy to miss.
Rodents in Missoula
Missoula was founded in 1860 and is now an urban city of about 77,000, known for the University of Montana and outdoor recreation. That outdoor focus matters for rodents, since sheds, garages, gear rooms and cabins are where deer mice settle. The climate is warm-summer continental, with highs near 86F, winter lows around 18F, about 15 inches of precipitation a year and humidity near 62 percent at roughly 3,209 feet. Dry air and cold nights push mice indoors in fall, and dry droppings become dust quickly. Montana's hantavirus numbers set the tone. The state health department reports 49 cases since 1993, 11 of them fatal, with patients ranging from 8 to 68 years old and a median age of 45. Exposure usually happens while cleaning cabins, sheds and outbuildings. With a median home value near $520,000, sealing up before fall protects both your health and your property.
Local research
Rodents in Missoula, MT: what the public record shows
Before you compare quotes, it helps to know which rodents actually live in Montana, when they are busiest around Missoula, and what the state figures look like. Everything below links to the agency or university page it came from.
Rodent species recorded in Montana
- 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 Missoula
Risk peaks when closed-up cabins, sheds and outbuildings are opened and cleaned in spring.
Montana DPHHS follows CDC's seal up, trap up, clean up sequence: never sweep or vacuum droppings.
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: Montana Department of Public Health and Human Services, Communicable Disease Epidemiology; 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 the house and garage by late August, before the fall rush indoors.
- Store camping gear, sleeping bags and tents in sealed plastic bins.
- Close up cabins with mouse-proof vent covers, door sweeps and sealed food.
- Keep firewood stacked away from the house and off the ground.
- Store birdseed and pet food in metal cans with tight lids.
- Put two or three snap traps in the garage in early fall to catch the first arrivals.
- Clear brush and tall grass back from foundations and outbuildings.
- Never sweep or vacuum droppings; always wet them first.
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?
Montana hantavirus patients have ranged in age from 8 to 68.
In eastern Montana, the white-footed mouse joins the deer mouse as a hantavirus carrier.
Montana did not appear in the CDC's provisional 2025 hantavirus table, though Idaho logged one case.
Questions people ask
How common is hantavirus in Montana?
Uncommon, but Montana's burden is heavy for its population. The state health department reports 49 cases since 1993 with 11 deaths, and a typical year brings zero to two cases. Six cases were reported from 2020 to 2025. For Missoula homes, the risk centers on cleaning sheds, cabins and garages where deer mice have been.
Which mice carry hantavirus in Missoula?
The deer mouse is the carrier across Montana, including Missoula. The white-footed mouse plays that role in eastern Montana. The house mouse, the common kitchen mouse, does not carry hantavirus. Deer mice have white bellies and bicolored tails. If you are not sure which mouse left the droppings, clean as though it was a deer mouse.
Is it safe to sweep out a shed with mouse droppings?
No. Montana health officials are clear: never sweep or vacuum droppings. Sweeping lifts dried particles into the air, and that is how hantavirus is inhaled. Air the shed out for 30 minutes, soak droppings with bleach solution at 1.5 cups per gallon, wait 5 minutes, then wipe up with paper towels and gloves.
When do mice come inside in Missoula?
Mostly September through November. Missoula winter lows average about 18F, and dry, cool nights arrive quickly at 3,209 feet. Mice head for garages, basements and walls early. Sealing in August is far more effective than trapping in December, when mice are already settled and breeding indoors.
Do I need a respirator to clean mouse droppings?
For a few droppings in an open, ventilated area, gloves and the wet cleaning method are usually enough. For a closed shed, cabin, crawlspace or heavily soiled space, a well-fitted respirator adds protection. If the job is large or cramped, consider hiring someone who has the gear and does this work regularly.
Are Norway rats a problem in Missoula?
Norway rats are on Montana's list of household rodents, but mice drive most complaints around Missoula. If you see large, blunt droppings or burrows beside a foundation, a rat may be involved, and the plan shifts toward outdoor sanitation and bait stations. Most homes here are dealing with house mice or deer mice.
How should I store camping gear to keep mice out?
Use sealed plastic bins with tight lids for sleeping bags, tents and clothing, and keep them off the floor. Never store food with gear. Check gear for droppings before use, and if you find any, clean the item outdoors with disinfectant. In a town known for outdoor recreation, a crowded gear room is an easy deer mouse target.
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Sources (6)
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