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.
- For South Portland homes, 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.
Homeowners, renters and landlords in South Portland who are hearing, seeing or smelling signs of rodents.
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.
- 1Scratching or scurrying sounds in walls or ceilings at night.
- 2Droppings in drawers, pantries, under sinks, or along walls.
- 3Bait or pet food vanishing from bowls overnight.
- 4Tracks or tail drag marks in dust or flour.
- 5Dead-animal odor that appears and slowly fades.
- 6Chewed holes in the bottom of cabinets or drawers.
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.
Treatment options and typical costs
Inspection and Entry-Point Mapping
$75–$250
Many credit the fee if you go ahead. Ask. Ask whether the report lists every entry point, because in South Portland that list is the real product.
- Time
- 60–90 minutes
- Best for
- Every job; nothing else works without it
Sealing and Rodent-Proofing
$200–$1,500, more for large or complex homes
Ask for a walkthrough of every sealed point, plus photos. A good South Portland company will photograph each repair so you know what was done and where to look later.
- Time
- 2–6 hours, sometimes a full day
- Best for
- Stopping re-entry for good; the lasting fix
Attic and Crawlspace Cleanup and Sanitation
$500–$3,000, higher if insulation is replaced
Scent trails attract new rodents. Cleanup helps the sealing hold. Deodorizing and sealing a South Portland attic makes it less inviting to the mice outside looking for a way in.
- Time
- Half day to two days
- Best for
- Heavy contamination; odor, urine-soaked insulation, nesting
Tamper-Resistant Exterior Bait Stations
$100–$300 setup, $40–$80 per service visit
Rodenticides are regulated, and some products are restricted to licensed applicators. Ask which product they use. Ask how they protect pets and wildlife.
- Time
- 30–45 minutes per visit, ongoing
- Best for
- Outdoor rat pressure; ongoing perimeter protection
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 South Portland.
Norway rats are the other usual suspect. They burrow along foundations and enter low. House mice are the most common rodent in South Portland homes. They're small, curious and breed quickly.
When they move in.
Spring is breeding season. Check for gaps before then. Small problems grow fast.
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.How they get into houses here.
Look at the dryer vent flap. Window wells need covers or screens. Homes from South Portland out to Portland and Scarborough share the same weak spots, so the checklist below works across the area. Plenty of homes in South Portland have basements. Rodents use gaps around utility lines, dryer vents and window wells. Check where pipes and cables enter.
A year of rodents in South Portland.
- Spring: breeding season. Act on any sign quickly. - Winter: with lows near 14°F in South Portland, check the attic, garage and pantry for droppings. - Fall: mice move indoors as nights cool. Seal gaps in September. - Summer: with highs around 78°F in South Portland, rodents look for water. Fix drips and leaks.
Mice or rats?
- Behavior: mice are curious about new traps. Rats avoid them for days. - Sounds: mice sound light and quick. Rats sound heavier. - Holes: mice chew dime-sized holes. Rats chew holes closer to quarter-sized. - Droppings: mouse droppings are rice-sized. Rat droppings are two or three times bigger. - Rub marks: rats leave greasy smudges along walls and beams.
Sealing small gaps yourself.
- Expanding foam: fine on top of mesh, useless on its own. - Door sweeps: close the gap under garage and exterior doors. - Hardware cloth: use quarter-inch mesh over vents and larger holes. - Sealant or mortar: cover the mesh so it stays put. - Steel wool or copper mesh: pack it into small gaps first. - Check your work: daylight through a gap means it isn’t sealed.
Cleaning up droppings safely.
- Don’t sweep or vacuum droppings dry. It stirs up dust. - Wipe up with paper towels and bag them. - Spray droppings with a bleach solution, then wait five minutes. - Wear rubber or plastic gloves. - Air the room out for 30 minutes first. - Wash your gloved hands, then your hands.
What happens at an inspection.
They check the foundation, vents, rooflines and utility gaps. The inspector walks the outside first. Most inspections take about an hour. Photos help. You should come away with a list of entry points. Inside, they check the kitchen, garage and attic.
Rodents in the car.
Park in a closed garage when you can. Mice and rats nest in engine bays and chew wiring. Clear birdseed and pet food from the garage. Check the air filter box for nesting.
Bird feeders and rodents.
Use a seed tray and sweep up spills. Spilled seed feeds mice and rats. Store seed in a metal can with a tight lid. If rodents show up, bring feeders in at night.
Questions to ask before you sign.
- Is cleanup included, or extra? - What happens if they come back? - How many trap visits are included? - Which gaps will you seal, and with what? - Where are they getting in? - Will you use poison inside? (Ask them not to.)
Rodents by the numbers.
For South Portland homes, those three findings — species, entry points, and scale — are what a quote should be built on, not a regional average. For South Portland homes, 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. For South Portland homes, what actually matters is a walk-through: where the droppings are, how the rodents are getting in, and how large the colony is.
What affects the price
- Exterior bait stations and ongoing service frequency.
- Age of the home and condition of the foundation.
- Emergency or short-notice scheduling.
- Whether sheds, garages or other outbuildings are included.
- Crawlspace or slab; crawlspaces add labor.
- Attic access and how much insulation is contaminated.
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What's your biggest concern about rodents?
When to call for help
Call right away if you see rats. They take a longer, more careful approach. Attic cleanup is hard to do safely without training. Call if you hear them in the attic or walls. Droppings in several rooms are another sign. So is a dead-rodent smell.
What you can do yourself
Seal small gaps with steel wool and sealant. Rooflines, vents and attics are harder. That's where a pro's sealing work pays off. Start tonight with snap traps along the walls. Bait them with peanut butter. Store food in sealed bins.
Rodents in South Portland
A typical home in South Portland is worth around $410k, and chewed wiring or soiled insulation can get expensive. In South Portland's neighborhoods, woodpiles, fences, bird feeders and gardens draw rodents close to the house. Winter lows average around 14°F in South Portland, and that cold is what sends mice looking for a way in. South Portland gets about 47 inches of rain a year, and heavy storms flood burrows, which pushes rats toward buildings.
Local research
Rodents in South Portland, ME: what the public record shows
Before you compare quotes, it helps to know which rodents actually live in Maine, when they are busiest around South Portland, and what the state figures look like. Everything below links to the agency or university page it came from.
Rodent species recorded in Maine
- 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.
When rodents are busiest around South Portland
Year-round; fall peak. Pacific Northwest: roof and Norway rats plus deer mice statewide in Washington.
Based on South Portland’s humid continental climate profile.
Maine CDC's hantavirus page says the virus is carried by certain rodents, including some rats and mice in the United States, and recommends seal up, trap up, clean up.
Rules that apply in Maine
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: Maine Center for Disease Control & Prevention; CDC; Pest Notes: House Mouse; Pest Notes: Rats. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep rodents away
- Clean up pet waste and do not leave bowls out overnight.
- Screen foundation and attic vents with quarter-inch hardware cloth.
- Trim tree branches at least six feet from the roof.
- Cover dryer and exhaust vents with metal louvered covers.
- Seal every gap larger than a quarter inch with metal mesh.
- Store pet food and birdseed in sealed metal containers.
Shared basements and utility rooms are where rodent problems in rentals usually start. Landlords should walk them each fall and after every tenant turnover.Did you know?
A house mouse can jump about a foot straight up.
For South Portland homes, a rodent's front teeth never stop growing, so it gnaws constantly to keep them worn down.
Questions people ask
How do I choose a rodent control company?
A good company talks about sealing, not just traps. Ask what happens if rodents come back. Ask how they seal gaps and what materials they use. Make sure they're licensed in Maine.
Do I need to replace attic insulation?
Ask the inspector to show you before you agree to replacement. Light activity can often be cleaned up. Only if it's heavily soiled or flattened by nesting.
Are rats a bigger problem than mice?
They also tend to need more sealing work outside. Rats are bigger, chew more, and avoid new traps for days. Usually.
What should be in a rodent control quote?
Cleanup should be listed separately. It should say what happens if they return. Entry points, sealing materials and the number of trap visits.
Do ultrasonic repellers work?
Sealing and trapping work better. It doesn't pass through walls either. Rodents get used to the sound within days. Not reliably.
Where in the house are mice most often found?
Expect a good pro in South Portland to connect their plan to what they actually found at your home. homeowners who had encountered rodents said they saw them in the kitchen, according to a September 2022 Harris Poll for the National Pest Management Association (NPMA). Thirty-seven percent of U.S. The kitchen leads.
Which parts of the U.S. have the most rodent problems?
As you collect quotes in South Portland, ask each company what they usually run into in your neighborhood. Census Bureau's 2019 American Housing Survey (AHS), separates the highest and lowest selected large metros for reported rodent signs. Where you live matters enormously: a 15.8-percentage-point gap, calculated from the published figures of the U.S. Older, denser metros in the Northeast report far more.
Are rodents a problem in South Portland?
They're common here, as almost everywhere. House mice cause most problems.
Nearby cities
Related guides
Sources (10)
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