The short version
Rodent control in the United States comes down to three jobs done together: sealing every gap larger than 1/4 inch, removing food and shelter, and trapping or baiting until activity stops. Which rodent you have and when it shows up depends on your region, so the plan for a Phoenix attic differs from one for a Boston basement.
- House mice, Norway rats, and roof rats are the three structural rodents almost everywhere.
- The CDC says a mouse fits through a 1/4-inch gap, so sealing must be that tight.
- Cold-climate homes see a fall migration; warm coastal states run roof rats all year.
- Deer mice in the West carry hantavirus, which changes how you clean up droppings.
- Rodenticide rules differ by state, so ask any provider what they are allowed to use.
This page is for anyone in the United States who has found evidence of mice or rats and wants a straight answer before hiring help. Homeowners, renters, landlords, and small-business owners will find the same core steps here, and every state has its own guide that builds on them.
What to look for
Control has to cover the whole property, not just the room where you saw one. Rats also range widely, foraging 100 to 500 feet from the nest, so the rat in your kitchen may live under a neighbor's shed. University of California pest notes put Norway rats at four to six litters a year, weaning 20 or more young. Breeding speed is why a small sighting becomes a large problem. In the West, the deer mouse joins the list, and it matters for a different reason: it is the main carrier of hantavirus. The roof rat is a climber that runs along fences and power lines and settles into attics, especially in warm coastal states. The Norway rat is a burrower that lives at or below ground level and favors basements, sewers, and foundations. The house mouse is the smallest and most widespread; it nests inside walls, cabinets, and stored boxes. Three rodents cause nearly all structural problems in American homes.
- 1Droppings the size of rice grains (mice) or olive pits (rats) along walls, in drawers, or under sinks.
- 2Scratching or scurrying in ceilings and walls that starts after dark and stops when you turn on a light.
- 3Gnaw marks on pantry packaging, pet food bags, plastic bins, or the corners of doors.
- 4Greasy rub marks along baseboards or pipes where rats run the same route every night.
- 5A stale, musky ammonia smell in a closet, garage, or attic that gets stronger in warm weather.
- 6Shredded insulation, paper, or fabric pulled into a ball inside a cabinet or engine bay.
Why it’s worth acting soon
- Populations grow quickly; a few mice in October are a colony by January.
- Chewed wiring in walls and attics is a fire hazard and often needs an electrician to repair.
- Urine and droppings soak into insulation, which then has to be removed and replaced.
- The CDC lists leptospirosis, salmonellosis, rat-bite fever, and hantavirus among diseases rodents spread directly.
- Rats undermine slabs, patios, and retaining walls with burrows that widen every season.
Treatment options and typical costs
Exclusion (sealing entry points)
Quoted after inspection
A technician walks the foundation, roofline, and utility penetrations and closes every opening larger than 1/4 inch with steel wool, hardware cloth, sheet metal, or mortar. It is the only step that stops the next infestation, and it matters most in older houses with settled foundations.
- Time
- One to two visits; permanent if maintained
- Best for
- Any home with repeat activity, especially pre-1980 construction
Snap and multi-catch trapping
Quoted after inspection
Traps set along walls and runways, checked and reset over two to four weeks. Trapping confirms the species, shows the population dropping, and avoids a rodent dying inside a wall. It is the default in states that restrict anticoagulant baits and the right choice in kitchens and bedrooms.
- Time
- Two to four weeks with follow-up checks
- Best for
- Mice and rats inside living space; homes with pets and children
Exterior bait stations
Quoted after inspection
Locked, tamper-resistant boxes placed along the outside of the building and near burrows. Rats feed for several days before dying, so this handles large outdoor populations that traps cannot keep up with. Which active ingredients are allowed depends on your state, so ask before signing.
- Time
- Ongoing, usually checked monthly or quarterly
- Best for
- Norway rat burrows, commercial properties, dense urban lots
Prices are typical published ranges. Ask what’s included before you compare quotes.
Rats can travel plumbing, so a sink or floor drain with a missing strainer is worth fixing; a tight strainer or grate keeps them out.Which rodents live in which part of the country?
West of the Mississippi, droppings in an outbuilding are a health question first and a pest question second. Provisional 2025 counts show 17 cases, with California, Arizona, and Colorado leading. It moves into cabins, garages, barns, and vacation homes, and it is the reason the CDC tracks hantavirus. The interior West adds the deer mouse. The job starts on a ladder rather than in the basement. It climbs, so the entry points are soffit gaps, roof returns, and the place where a palm frond or oak limb touches the shingles. Across the Southeast, Gulf Coast, and Pacific coast, the roof rat takes over. Norway rats burrow under stoops and slabs and come up through basements, so control there means exterior stations around the foundation and traps at ground level. In the Northeast and upper Midwest, house mice and Norway rats are the pair you will meet. The species mix changes with the map, and it decides how a provider sets up the job.
A month-by-month look at rodent activity in the United States.
Desert cities see the opposite pattern, with rodents pushing indoors in July and August for water rather than warmth. In warm coastal states this calendar barely applies: roof rats breed in attics in every season, with only a lull on the hottest afternoons. March through May brings spring litters, and populations that overwintered indoors double. Indoor trapping is the main winter work, because the outdoor population is not replacing what you remove. Rodents that got in are nesting in walls and insulation, and this is when most homeowners first hear scratching. December through February is the quiet indoor period. Sealing done in August pays off more than any trap set in December. Field mice and Norway rats lose their outdoor food and shelter as nights drop below freezing, and they follow warm air leaking from foundations, garage doors, and dryer vents. September through November is the move-in season for the northern half of the country.
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.What happens on the first visit from a rodent control company?
A quote that only lists bait stations and a monthly fee is a maintenance contract, not a fix, and it is fair to say so. Before they leave, ask for three things in writing: a list of every entry point found, the sealing materials, and the number of follow-up visits included. Mice are trapped inside; rats often need exterior stations across the lot, since they forage 100 to 500 feet from the nest. Expect them to identify the species from droppings and gnaw marks, because a mouse plan and a rat plan are different. Inside, they check under sinks, behind appliances, along the top of foundation walls, and in the attic for droppings, rub marks, and nesting material. The technician should walk the entire exterior at ground level and at the roofline, checking pipe penetrations, weep holes, garage door seals, soffit vents, and the gap where siding meets foundation. A good first visit is mostly looking, not spraying.
Cleaning up droppings without making yourself sick.
For attics where insulation is soiled, pay a provider with respirators and bagging, since you cannot ventilate a sealed attic on your own. Never sweep or vacuum, because that turns droppings into airborne dust. Pick everything up with paper towels, bag it, and mop the surrounding surfaces with the same solution. Mix 1.5 cups of household bleach into a gallon of water, spray the droppings and nesting material until soaked, and wait five minutes. Put on rubber gloves. Start by opening windows and doors and leaving the space for 30 minutes so the air exchanges. Even east of the Mississippi, where those mice are rare, the same steps protect you from salmonella and leptospirosis. The CDC recorded 890 cases from 1993 through 2023 and 35 percent were fatal, almost always after someone stirred up dried deer-mouse droppings in an enclosed space. Cleanup has rules, and they exist because of hantavirus.
How to compare two rodent control quotes.
Finally, ask whether attic cleanup and insulation replacement are included, since that line can be larger than the pest work itself. In California most anticoagulant baits are off the table for residential use, which pushes work toward trapping and sealing. Third, ask about bait rules where you live. Count the visits, not the words. Bait stations need periodic checks by law in many states. Trapping needs return visits over two to four weeks to reset traps and confirm activity has stopped. Second, check the follow-up schedule. One that lists only traps and bait is doing the temporary work. A quote that lists specific entry points and the materials used to close them is doing the permanent work. First, look for exclusion. The difference is usually scope, so compare the pieces rather than the total. Two quotes for the same house can be hundreds of dollars apart and both be honest.
What affects the price
- How many entry points the inspection finds, since each one is sealed and priced separately.
- Whether the problem is mice, which stay inside, or rats, which need exterior stations across the lot.
- Attic access and pitch: a steep roof or a tight crawlspace slows every visit.
- Insulation removal and replacement when nests have been there for a season or more.
- State bait restrictions, which shift the work toward labor-heavy trapping and exclusion.
- The length of the follow-up schedule, from two visits to a year of quarterly checks.
When to call for help
Call a rodent control company when you find droppings in more than one room, hear activity in walls or ceilings, or see a rat in daylight, which usually means the population is crowded. Call right away if the droppings are in a shed, cabin, or garage in a western state, because deer mice there carry hantavirus and cleanup should follow CDC steps. Landlords and restaurant owners should call at the first sign, since the paperwork arrives faster than the rodents. A provider should offer an inspection that maps entry points, not just a box of bait.
What you can do yourself
If you have trapped for three weeks and still see fresh droppings, get an inspection. The value is the person who finds the hole you missed. A professional brings the inspection, the exclusion materials, state-legal bait if needed, and a follow-up schedule. Rats are wary of new objects, forage across the whole lot, and dig under slabs, and finding the entry point on a two-story house usually takes a ladder and experience. Where DIY fails is rats and repeat infestations. Many homeowners get there. You can handle a light mouse problem yourself if you do three things properly: set a dozen snap traps along walls with peanut butter, seal every gap you can find with steel wool and caulk, and keep food in hard containers for a month.
Where you live matters
residents in early 2026 and 46 in Puerto Rico. The Gulf and Atlantic coasts, Southern California, and the Texas coast run roof rats in attics and palms every month, and humid conditions there keep leptospirosis on the CDC's radar, with 21 cases counted among U.S. Rodent pressure in the United States splits along climate lines. Cities with large stocks of pre-1980 homes have settled foundations, unscreened vents, and original garage doors, and those are the gaps that let rodents in. Housing matters as much as weather. The interior West carries the hantavirus story: of the 17 provisional cases reported for 2025, western states accounted for all but three. The northern tier, from Washington through the Great Lakes to New England, sees house mice and Norway rats pour into basements each fall as fields freeze.
Simple ways to keep rodents away
- Stuff steel wool into gaps around pipes and cables, then seal over it with caulk or foam so it stays put.
- Install a door sweep on every exterior door; a rat needs only a 1/2-inch gap underneath.
- Keep firewood, lumber, and pavers at least 20 feet from the house and off the ground.
- Trim tree limbs so nothing touches the roof, which is the roof rat's highway in warm states.
- Store bird seed, pet food, and grass seed in metal or heavy plastic bins with tight lids.
- Cover dryer and attic vents with 1/4-inch hardware cloth, not window screen, which rodents chew through.
In a commercial kitchen, the weak points are the floor drain, the gaps behind equipment and the back door. A monthly walk-through catches problems before an inspector does.Did you know?
A mouse can pass through a hole the width of a pencil, which is why the CDC's seal-up guidance targets any gap of 1/4 inch or more.
Roof rats produce three to five litters a year with up to eight young each, which is how a warm attic fills in a single season.
The CDC's list of diseases spread directly by rodents includes rat-bite fever, tularemia, and lymphocytic choriomeningitis, not only hantavirus.
Questions people ask
What kind of rodent do I most likely have in my house?
In the West, garage droppings may be from deer mice. Roof rats dominate warm coastal states such as Florida, Texas, and California, where they live in attics all year. Norway rats dominate cold northern cities with sewers and basements. Most homes in the United States have house mice, and the rat answer shifts by region.
When do rodents move into houses in the United States?
Desert regions see a smaller indoor push in summer heat as rodents look for water. Warm coastal states have no off season; roof rats nest in attics year-round. In cold climates the big move is September through November, when mice and Norway rats leave fields for heated structures.
How small a gap can a mouse get through?
That is why exclusion uses steel wool, hardware cloth, and flashing rather than foam alone. Rats need a bit more, but they chew a 1/4-inch hole larger overnight. A mouse fits through a 1/4-inch opening, about the width of a pencil, according to the CDC.
Is hantavirus a real risk from mice in my house?
East of the Mississippi the risk is very low. Deer mice are the carrier, and exposure usually happens while cleaning droppings in a shed, cabin, or garage. The CDC counted 890 hantavirus cases from 1993 through 2023, and 94 percent were west of the Mississippi. It depends on where you live.
How do I safely clean up rodent droppings?
Open the windows for 30 minutes and leave the room, then spray the droppings with a bleach solution of 1.5 cups per gallon of water and let it soak five minutes before wiping with paper towels. The CDC says never sweep or vacuum, because dust from dried droppings is how hantavirus reaches your lungs.
Are rat poisons legal to use at home?
Ask any provider exactly what they are licensed to apply in your state. Bromethalin, cholecalciferol, and zinc phosphide products remain in more places. California prohibits most uses of first- and second-generation anticoagulant baits, and other states are tightening rules. It depends on your state and the product.
Should I worry about plague from rodents?
Fleas from wild rodents are the vector. The CDC reports an average of seven human plague cases a year in the United States, concentrated in northern New Mexico, northern Arizona, southern Colorado, and parts of California, southern Oregon, and far western Nevada. Only in a narrow band of the West.
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