The short version
Trap the ones inside, then seal the gaps. An inspection usually costs $75–$250.
- Look for droppings, gnaw marks and night-time scratching.
- Across Great Falls, mice usually start moving indoors in September and October, as nights get colder.
- Traps remove them; sealing keeps them out.
- Never sweep or vacuum droppings dry.
Anyone in Great Falls dealing with mice or rats, or hoping to keep them out.
What to look for
A mouse fits through a gap the size of a dime. Seeing one in daylight usually means there are more. Rodents are mostly unseen. You hear them at night and find droppings by morning.
- 1Burrow holes along the foundation, deck, or shed.
- 2Live sighting, especially during the day.
- 3Greasy rub marks along baseboards, beams, and pipe runs.
- 4Shredded paper, fabric, or insulation gathered into a nest.
- 5Disturbed insulation or tunnels in the attic.
- 6Dead-animal odor that appears and slowly fades.
Why it’s worth acting soon
- Mice breed fast, every few weeks.
- Droppings and urine contaminate food and insulation.
- Gnawed wiring can be a fire risk.
- Nests and odor get harder to clean the longer they stay.
- Deer mice can carry hantavirus.
Treatment options and typical costs
Inspection and Entry-Point Mapping
$75–$250
Across Great Falls, a rodent inspection begins outdoors, checking the foundation, rooflines and utility lines for gaps. Indoors, they check attics, crawlspaces and behind appliances.
- Time
- 60–90 minutes
- Best for
- Every job; nothing else works without it
Tamper-Resistant Exterior Bait Stations
$100–$300 setup, $40–$80 per service visit
Bait stations belong outside, not in the attic. A Great Falls pro places them along fence lines, near sheds, and beside foundations where rats travel, then services them monthly or quarterly.
- Time
- 30–45 minutes per visit, ongoing
- Best for
- Outdoor rat pressure; ongoing perimeter protection
Snap-Trap Program
$150–$400 per visit
Trapping works best alongside sealing. Alone, it only lowers the count. After sealing, the last traps confirm the house is clear.
- Time
- 30–60 minutes per visit, 2–4 visits
- Best for
- Active indoor infestations; fast results you can see
Follow-Up Monitoring
$50–$150 per visit, or included in a plan
Ask what happens if activity returns during the monitoring period. Many re-trap and re-seal under the same agreement. Confirm first.
- Time
- 20–40 minutes per visit
- Best for
- Confirming the house stays clear after treatment
Prices are typical published ranges. Ask what’s included before you compare quotes.
Clutter gives mice cover. Keeping stored fabric in lidded bins and off the floor takes away the nesting spots they like best.Which rodents live around Great Falls.
They're small, curious and breed quickly. Norway rats are the other usual suspect. They burrow along foundations and enter low. Deer mice live around Great Falls too, mostly near open land and in sheds or cabins. They can carry hantavirus, so clean up their droppings carefully. House mice are the most common rodent in Great Falls homes.
When they move in.
Check for gaps before then. Spring is breeding season. Small problems grow fast.
A metal vent cover with a working flap keeps mice out all winter. Plastic flaps crack in the cold and get chewed open.How they get into houses here.
Window wells need covers or screens. Plenty of homes in Great Falls have basements. Rodents use gaps around utility lines, dryer vents and window wells. Check where pipes and cables enter. Look at the dryer vent flap.
A year of rodents in Great Falls.
- Fall: mice move indoors as nights cool. Seal gaps in September. - Winter: with lows near 13°F in Great Falls, check the attic, garage and pantry for droppings. - Spring: breeding season. Act on any sign quickly. - Summer: with highs around 85°F in Great Falls, rodents look for water. Fix drips and leaks.
Mice or rats?
- Droppings: mouse droppings are rice-sized. Rat droppings are two or three times bigger. - Holes: mice chew dime-sized holes. Rats chew holes closer to quarter-sized. - Sounds: mice sound light and quick. Rats sound heavier. - Behavior: mice are curious about new traps. Rats avoid them for days. - Rub marks: rats leave greasy smudges along walls and beams.
Sealing small gaps yourself.
- Steel wool or copper mesh: pack it into small gaps first. - Sealant or mortar: cover the mesh so it stays put. - Hardware cloth: use quarter-inch mesh over vents and larger holes. - Door sweeps: close the gap under garage and exterior doors. - Expanding foam: fine on top of mesh, useless on its own. - Check your work: daylight through a gap means it isn’t sealed.
Cleaning up droppings safely.
- Air the room out for 30 minutes first. - Wear rubber or plastic gloves. - Spray droppings with a bleach solution, then wait five minutes. - Wipe up with paper towels and bag them. - Don’t sweep or vacuum droppings dry. It stirs up dust. - Wash your gloved hands, then your hands.
What happens at an inspection.
You should come away with a list of entry points. Photos help. Most inspections take about an hour. The inspector walks the outside first. They check the foundation, vents, rooflines and utility gaps. Inside, they check the kitchen, garage and attic.
Rodents in the car.
Clear birdseed and pet food from the garage. Mice and rats nest in engine bays and chew wiring. Park in a closed garage when you can. Check the air filter box for nesting.
Bird feeders and rodents.
Store seed in a metal can with a tight lid. Spilled seed feeds mice and rats. Use a seed tray and sweep up spills. If rodents show up, bring feeders in at night.
Questions to ask before you sign.
- Where are they getting in? - Which gaps will you seal, and with what? - How many trap visits are included? - What happens if they come back? - Is cleanup included, or extra? - Will you use poison inside? (Ask them not to.)
Rodents by the numbers.
Across Great Falls, what actually matters is a walk-through: where the droppings are, how the rodents are getting in, and how large the colony is. Across Great Falls, those three findings — species, entry points, and scale — are what a quote should be built on, not a regional average. Across Great Falls, ask any provider to show you the entry points and the plan before you compare numbers. National surveys set rough expectations but cannot diagnose one house.
What affects the price
- Age of the home and condition of the foundation.
- Number of entry points found during inspection.
- Whether sheds, garages or other outbuildings are included.
- Outdoor pressure from creeks, alleys, or restaurants nearby.
- Home size, stories, and roofline complexity.
- Mice versus rats; rats take longer and cost more.
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What's your biggest concern about rodents?
When to call for help
Attic cleanup is hard to do safely without training. They take a longer, more careful approach. Call right away if you see rats. So is a dead-rodent smell. Droppings in several rooms are another sign. Call if you hear them in the attic or walls.
What you can do yourself
Start tonight with snap traps along the walls. Bait them with peanut butter. Store food in sealed bins. Seal small gaps with steel wool and sealant. Rooflines, vents and attics are harder. That's where a pro's sealing work pays off.
Rodents in Great Falls
In Great Falls's neighborhoods, woodpiles, fences, bird feeders and gardens draw rodents close to the house. A typical home in Great Falls is worth around $245k, and chewed wiring or soiled insulation can get expensive. Great Falls only gets about 14 inches of rain a year, so local rodents look for water: drip lines, pet bowls and leaky hose bibs. Winter lows average around 13°F in Great Falls, and that cold is what sends mice looking for a way in.
Local research
Rodents in Great Falls, 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 Great Falls, 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 Great Falls
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
- Stack firewood off the ground and away from the house.
- Fill gaps around pipes, cables, and AC lines with copper mesh.
- Cap chimneys and repair damaged roof vents.
- Declutter garages and attics to remove nesting cover.
- Keep ivy, shrubs, and firewood away from the foundation.
- Install brush or rubber door sweeps on exterior doors.
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?
Across Great Falls, rats are strong swimmers and can tread water for a long time, which is why they sometimes travel sewer lines.
Across Great Falls, rats make ultrasonic chirps when they're tickled, which researchers compare to laughter.
Questions people ask
Will rodent control harm my pets?
Bait stations are locked. Tell the company about your pets before they start. It shouldn't. Traps go where pets can't reach.
Will rodents leave on their own?
Rarely. Once they've found food, water and a warm nest, they stay.
How do I choose a rodent control company?
Ask what happens if rodents come back. A good company talks about sealing, not just traps. Make sure they're licensed in Montana. Ask how they seal gaps and what materials they use.
Do I need to replace attic insulation?
Light activity can often be cleaned up. Ask the inspector to show you before you agree to replacement. Only if it's heavily soiled or flattened by nesting.
How do I know if I have mice or rats?
Mouse droppings are about the size of a rice grain. Rats also chew larger holes and sound heavier at night. Check the droppings.
Does a house with structural problems attract more rodents?
Census Bureau's 2019 American Housing Survey (AHS) found that occupied homes with sloping, leaning or buckling exterior walls were 5.6 times as likely to report rodent sightings as other homes, an association among resident reports, not proof the walls caused the rodents. For a home in Great Falls, the next step is an inspection that finds the source. The two go together, at least in the data. The U.S.
Do wealthier homes get fewer mice and rats?
Across Great Falls, rodents do not check tax returns: 52% of U.S. homeowners earning $100,000 or more reported a lifetime rodent encounter in the 2022 NPMA/Harris Poll, no lower than homeowners overall. Not according to homeowner surveys.
Are rodents a problem in Great Falls?
They're common here, as almost everywhere. House mice cause most problems.
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Sources (9)
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 September 11, 2026 · How we write these guides