The short version
Rodent control in Tacoma, Washington, is a year-round job because the mild marine climate never gets cold enough to slow rats down. Roof rats settle into Puget Sound attics and Norway rats work crawlspaces and foundations. Seal every quarter-inch gap, since Washington wildlife officials say rats chew small holes larger, then trap the animals already inside and clean droppings with bleach solution.
- Roof rats live in Puget Sound attics through every season, not just fall.
- Tacoma's 36F winter lows are too mild to thin rat numbers.
- WDFW reports 6 to 10 young per rat litter, breeding again at 3 to 4 months.
- Torn crawlspace vent screens give Norway rats an easy way in.
- Deer mice carrying hantavirus live throughout Washington, so clean droppings wet.
This is for Tacoma homeowners hearing scratching in the attic or under the floor, renters who need a landlord to fix a crawlspace vent or a gap at the roofline, and owners of small businesses near the waterfront or in commercial areas. It also helps anyone with a shed, garage or detached shop where mouse droppings have been building up.
What to look for
All four of Washington's structural rodents show up in Tacoma: roof rats, Norway rats, house mice and deer mice. Roof rats are the climbers, and in the Puget Sound area they are well known for living in attics year-round. They travel along tree branches, fences and utility lines and get in at roof vents, eaves and gaps around chimneys. Norway rats are diggers that live in burrows along foundations, under decks and in crawlspaces, and in a port city, any docks, warehouses or dumpsters near you add food and shelter. House mice nest in walls and cabinets, and deer mice move into sheds, garages and outbuildings. Tacoma's climate gives them steady conditions. Humidity averaging 75 percent and 40 inches of rain keep crawlspaces damp and wood soft, which makes chewing easier. Winter lows near 36F are mild, so rats breed through the year, though activity still peaks in fall. The Washington Department of Fish and Wildlife says rats can fit through a quarter-inch hole and chew it larger.
- 1Scratching or running in the attic in the hours after dark, often near the eaves.
- 2Droppings on top of insulation, along rafters or on the crawlspace vapor barrier.
- 3Torn or pushed-in crawlspace vent screens.
- 4Burrows along the foundation, under decks or beneath dense shrubs.
- 5Tracks about half an inch long in crawlspace dirt or on dusty surfaces.
- 6Gnawed wiring, ductwork or insulation in the attic or crawlspace.
- 7Rats moving along fences, branches or power lines at dusk.
Why it’s worth acting soon
- WDFW says rats can breed at 3 to 4 months, so numbers build quickly in a mild climate.
- Attic and crawlspace wiring and ductwork can be damaged, raising fire and repair costs.
- Urine-soaked insulation in damp crawlspaces holds odor and may need replacement.
- Deer mouse droppings in sheds and garages raise hantavirus risk during cleanup.
- Rats spreading between homes can turn a single problem into a neighborhood one.
Treatment options and typical costs
Roofline and crawlspace exclusion
Quoted after inspection
Gaps at roof vents, eaves, chimneys and pipe penetrations are sealed, and crawlspace vents get heavy-gauge screening. WDFW notes rats can enlarge a quarter-inch hole, so materials should be hardware cloth, sheet metal or mortar. This is the step that stops new rats from moving in.
- Time
- One to three days
- Best for
- Homes with attic or crawlspace activity
Attic and crawlspace trapping
Quoted after inspection
Snap traps along rafters, top plates and crawlspace runways remove rats already inside. Follow-up visits reset traps until catches stop. Trapping avoids rats dying in walls or under floors, where odor is hard to reach.
- Time
- Two to four weeks
- Best for
- Active rats in attics or crawlspaces
Insulation and vapor barrier cleanup
Quoted after inspection
After rats are gone, droppings, nests and soiled insulation are removed using wet cleaning: ventilate, soak with bleach solution, wait 5 minutes, then wipe and bag. In damp crawlspaces, a torn or soiled vapor barrier may need replacement, often quoted separately.
- Time
- One to several days
- Best for
- Attics and crawlspaces with long-term activity
Exterior bait stations
Quoted after inspection
Locked stations along the foundation or fence line can cut outdoor rat numbers near waterfront, commercial or wooded areas. They should be tamper resistant and placed away from pets and children. Bait supports sealing but does not replace it.
- Time
- Ongoing service
- Best for
- Properties with heavy outdoor pressure
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.Roof rats in Puget Sound attics: why Tacoma has them all year.
The reason is climate. Winter lows average around 36F and summer highs only reach about 77F. There is no hard freeze to thin rat populations and no extreme heat to drive them out of attics. Rats stay active and keep breeding, though activity still peaks in fall. Roof rats are climbers. They move along tree branches, fences and utility lines and get onto roofs, then enter through vents, eaves and gaps around chimneys and pipes. Once inside, they nest in insulation and travel along rafters, which is why people hear them overhead in the hours after dark. WDFW notes a rat can get through a quarter-inch hole and chew it larger, so sealing has to be thorough. Trim branches back from the roof, screen vents with heavy-gauge hardware cloth, and seal gaps with metal or mortar. Then trap what is still inside. Roof rats living in attics are a well-known Puget Sound pattern, and Tacoma is part of it.
A port city's rats: Norway rats near the waterfront.
Docks, warehouses, dumpsters and loading areas offer Norway rats food and shelter, and where those sit close to homes, rats can move from commercial blocks into nearby Tacoma yards. Norway rats burrow. They dig along foundations, under decks and in dense vegetation, and they come into homes at ground level through crawlspace vents, gaps around pipes and garage doors. If you live or run a business near the waterfront or commercial areas, focus on ground-level sealing. Replace torn crawlspace vent screens, seal pipe gaps, keep garbage in sealed bins, and check for burrows along the foundation. Exterior bait stations may help where pressure is heavy. Tacoma is a port city, and WDFW describes both the Norway rat and the roof rat as Old World rats rather than native species.
This is what a proper seal looks like: metal mesh fastened with screws and sealed at the edges. Foam or caulk on its own gets chewed through.Damp crawlspaces and wet winters.
That moisture shows up in crawlspaces, and it affects rodents. Damp crawlspaces are attractive to Norway rats and mice. They are sheltered, dark and rarely disturbed. Moisture also rusts metal vent screens and softens wood, making it easier for rodents to get in. Common problems include torn or rusted vent screens, gaps around pipes and ducts, and torn vapor barriers. Once inside, rodents nest in insulation and travel along joists. Checking your crawlspace a few times a year helps. Look for droppings on the vapor barrier, tracks in the dirt, and torn insulation. WDFW notes rat footprints are about half an inch long, so tracks are often easy to spot. If you find activity, replace vent screens with heavy-gauge hardware cloth, seal gaps with metal or mortar, and have soiled insulation and vapor barrier removed and replaced. Tacoma gets about 40 inches of rain a year, and humidity averages around 75 percent.
Hantavirus risk in western Washington.
Cases are rare. Washington sees 1 to 5 a year, and about 1 in 3 people diagnosed have died. Washington reported 1 case in 2025 in provisional CDC data. Across Tacoma, check sheds, garages, detached shops and crawlspaces for deer mice, especially near wooded areas. Deer mice have white bellies and sharply two-toned tails. Stirring up dried droppings or nests puts the virus into the air you breathe. Before cleaning, open the space and leave it for 30 minutes. Wear gloves, spray droppings with a bleach solution of 1.5 cups per gallon, and let it soak 5 minutes. Wipe up and bag everything. Never sweep or vacuum. For heavy contamination, consider hiring help. Hantavirus is often thought of as a desert or rural problem, but the Washington State Department of Health says infected deer mice live throughout the state, including western Washington.
Rats in a Tacoma rental: what tenants and landlords should do.
Tenants should put the complaint in writing, with dated photos of droppings or damage. Note where you hear activity, such as the attic or under the floor, and where you find droppings. Ask whether the plan includes sealing entry points, since traps alone will not stop new rats in a city where they stay active year-round. If you own the property, focus on the roofline and crawlspace. Roof rats in attics and Norway rats in crawlspaces both need sealing. In damp Tacoma conditions, check crawlspace vent screens for rust and tears. In multi-unit buildings, rodents can move through shared walls and crawlspaces, so inspect neighboring units too. A written plan from the provider, listing openings sealed, traps placed and follow-up visits, keeps everyone on the same page. When rodents turn up in a Tacoma rental, clear communication helps get them fixed.
What affects the price
- The number of roof vents, eaves and chimney gaps to seal.
- Crawlspace condition, including vent screens and vapor barrier.
- How much insulation in the attic or crawlspace is soiled.
- Trees and shrubs that need trimming away from the roof.
- Whether nearby docks, dumpsters or commercial buildings call for exterior stations.
- The number of follow-up trap visits included.
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What's your biggest concern about rodents?
When to call for help
Call a professional if you hear rats in the attic or under the floor for more than a few nights, find droppings in more than one area, or see torn crawlspace vents. Across Tacoma, roof rats in attics are common enough that any overhead noise deserves an inspection. Crawlspace work, with tight access and damp conditions, is usually better handed off. Also call before cleaning a shed, garage or crawlspace with heavy droppings, since the Washington State Department of Health says infected deer mice live throughout the state.
What you can do yourself
Some rodent work in Tacoma is easy to do yourself. Trim branches back from the roof, replace worn door sweeps, keep garbage in sealed bins and store birdseed and pet food in metal containers. A few mice in a kitchen usually respond to snap traps along the walls. Rats in attics and crawlspaces are harder. Roof rat entries are along the roofline, often at vents and eaves, and sealing them takes ladder work and the right materials. Crawlspaces are tight, damp and hard to work in, and Norway rats there may also have burrows outside. Cleanup of soiled insulation and vapor barrier is unpleasant and needs care. A provider can handle sealing, trapping and cleanup as one job.
Rodents in Tacoma
Tacoma is a port city of about 222,000 people, founded in 1875 and known for its Museum of Glass. Several local details shape the rodent picture. The marine west coast climate keeps winter lows around 36F and summer highs near 77F, so rats never face a hard season and stay active year-round, with a peak in fall. About 40 inches of rain a year and humidity near 75 percent keep crawlspaces damp and wood soft. As a port city, Tacoma has waterfront and commercial areas, and if your home or shop sits near docks, warehouses or dumpsters, Norway rats have food and shelter close by. Roof rats in Puget Sound attics are a well-known regional pattern. The city sits at about 243 feet, and wherever a wooded lot or green space backs onto a yard, rodents have cover close at hand. With a median home value around $470,000, sealing a home properly protects a significant investment.
Local research
Rodents in Tacoma, WA: what the public record shows
Before you compare quotes, it helps to know which rodents actually live in Washington, when they are busiest around Tacoma, and what the state figures look like. Everything below links to the agency or university page it came from.
Rat litter size
Old World rats are not regulated; killing is unrestricted.
WDFWRat entry hole
Footprint about 1/2 inch long; incisors grow 5 inches a year.
WDFWRodent species recorded in Washington
- 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.
- Roof rat (Rattus rattus) — Climber of attics and trees in warm and coastal regions; tail longer 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 Tacoma
Year-round; roof rats in Puget Sound attics.
Rules that apply in Washington
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: Hantavirus; WDFW; 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
- Trim tree branches and shrubs at least a few feet back from the roof.
- Replace torn crawlspace vent screens with heavy-gauge hardware cloth.
- Seal gaps around pipes, chimneys and vents with metal or mortar.
- Keep garbage in sealed bins away from the house.
- Store birdseed and pet food in metal containers.
- Clear dense vegetation and debris along the foundation.
- Check the attic and crawlspace a few times a year for droppings.
- Air out sheds and garages for 30 minutes before cleaning.
In a multi-unit building, mice move between apartments through shared walls and pipe chases, so treating one unit rarely solves it. Ask for a building-wide plan.Did you know?
Washington wildlife officials classify Norway and roof rats as Old World rats, species that are not native to North America.
Rat pregnancies last only about 3 weeks, according to WDFW.
The CDC lists salmonellosis and leptospirosis among illnesses rodents can spread directly through droppings and urine.
Questions people ask
Why do Tacoma attics get roof rats?
Roof rats are well known in Puget Sound attics, and Tacoma's mild climate, with winter lows around 36F, lets them stay active all year. They climb trees, fences and utility lines and enter through roof vents, eaves and chimney gaps. Trimming branches and sealing the roofline is the fix.
Are rats protected wildlife in Washington?
No. The Washington Department of Fish and Wildlife says Norway and roof rats, which it calls Old World rats, are not regulated and killing them is unrestricted. That means you can trap them on your property. Keep traps away from pets and children.
What does a damp crawlspace have to do with rats?
Norway rats burrow and nest at ground level, and crawlspaces offer shelter. Across Tacoma, with about 40 inches of rain a year, crawlspaces stay damp and vent screens rust or tear. Replace torn screens with heavy-gauge hardware cloth and check for burrows along the foundation.
How many hantavirus cases does Washington have?
The Washington State Department of Health reports 1 to 5 cases a year, with about 1 in 3 people diagnosed having died. Infected deer mice live throughout the state. Before cleaning droppings, ventilate for 30 minutes and soak them with bleach solution.
How fast do rats multiply?
WDFW says rats have 6 to 10 young after about 3 weeks of gestation, and the young can breed at 3 to 4 months. In a mild climate, that cycle continues most of the year, so a small attic problem can grow quickly.
Is the waterfront a source of rats?
Port and commercial areas can support Norway rats, which find food and shelter around docks, warehouses and dumpsters. Across Tacoma, homes and businesses near those areas may see more pressure. Sealing low entry points and keeping garbage secured helps.
How do I tell rat tracks from mouse tracks?
WDFW says rat footprints are about half an inch long, much larger than mouse tracks. Crawlspace dirt and dusty attic surfaces often show tracks clearly. Rat droppings are also larger and capsule-shaped, while mouse droppings are small and pointed.
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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