The short version
Trap the ones inside, then seal the gaps. Around Pasadena, check the roofline too, since roof rats come in high. An inspection usually costs $75–$250.
- Look for droppings, gnaw marks and night-time scratching.
- Winters around Pasadena are mild, so rodents stay active all year.
- Traps remove them; sealing keeps them out.
- Never sweep or vacuum droppings dry.
Homeowners, renters and landlords in Pasadena 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.
- 1Bait or pet food vanishing from bowls overnight.
- 2Shredded paper, fabric, or insulation gathered into a nest.
- 3Greasy rub marks along baseboards, beams, and pipe runs.
- 4Scratching or scurrying sounds in walls or ceilings at night.
- 5Pets staring at or pawing at a wall or appliance.
- 6A musky or ammonia-like smell in closed rooms.
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
Expect a flashlight, a mirror, and a lot of crouching. In Pasadena homes, the usual entry points are garage door corners, dryer vents, gaps around pipes, and roof-to-fascia joints.
- Time
- 60–90 minutes
- Best for
- Every job; nothing else works without it
Snap-Trap Program
$150–$400 per visit
Traps are preferred indoors over poison because there is no carcass rotting in a Pasadena wall cavity. They remove catches and adjust trap positions between visits.
- Time
- 30–60 minutes per visit, 2–4 visits
- Best for
- Active indoor infestations; fast results you can see
Tamper-Resistant Exterior Bait Stations
$100–$300 setup, $40–$80 per service visit
Locked bait stations around a Pasadena home's perimeter reduce the outdoor rat population before it reaches the walls. Anchored and locked, they keep children, pets, and wildlife out.
- Time
- 30–45 minutes per visit, ongoing
- Best for
- Outdoor rat pressure; ongoing perimeter protection
Follow-Up Monitoring
$50–$150 per visit, or included in a plan
Fresh droppings look dark and soft; old ones look gray. That tells a pro whether activity is current.
- 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.
Roof rats and mice love attic insulation. Tunnels through the fluff, flattened runways and droppings along the eaves are the signs to look for.Which rodents live around Pasadena.
They can carry hantavirus, so clean up their droppings carefully. Deer mice live around Pasadena too, mostly near open land and in sheds or cabins. They climb, and come in high through attic vents and branches. Roof rats are common around Pasadena too. They burrow along foundations and enter low. Norway rats are the other usual suspect. They're small, curious and breed quickly. House mice are the most common rodent in Pasadena homes.
When they move in.
Small problems grow fast. Spring is breeding season. Listen for them in the attic after dark. Roof rats are active all year. Activity still rises in fall and winter, even here.
A good inspection starts outside at ground level: door thresholds, the joint between siding and foundation, and anywhere a pipe or cable enters.How they get into houses here.
Trim branches back from the roof. For roof rats, check soffit vents, gable vents and eaves. Homes from Pasadena out to Glendale and Los Angeles share the same weak spots, so the checklist below works across the area. Daylight under a door means a gap. Look behind the washer and under sinks. Check the bottom corners of the garage door. Garage seals, brick weep holes and pipe gaps are typical entries. Many homes in Pasadena sit on slabs.
A year of rodents in Pasadena.
- Summer: with highs around 88°F in Pasadena, rodents look for water. Fix drips and leaks. - Spring: breeding season. Act on any sign quickly. - Winter: with lows near 46°F in Pasadena, check the attic, garage and pantry for droppings. - Fall: activity rises as rodents settle in for winter. Check the attic and garage.
Mice or rats?
- Rub marks: rats leave greasy smudges along walls and beams. - 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.
Sealing small gaps yourself.
- Check your work: daylight through a gap means it isn’t sealed. - 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.
Cleaning up droppings safely.
- Wash your gloved hands, then your hands. - 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.
What happens at an inspection.
Photos help. You should come away with a list of entry points. Inside, they check the kitchen, garage and attic. They check the foundation, vents, rooflines and utility gaps. The inspector walks the outside first. Most inspections take about an hour.
Rodents in the car.
Clear birdseed and pet food from the garage. Check the air filter box for nesting. Park in a closed garage when you can. Mice and rats nest in engine bays and chew wiring.
Bird feeders and rodents.
Store seed in a metal can with a tight lid. If rodents show up, bring feeders in at night. Use a seed tray and sweep up spills. Spilled seed feeds mice and rats.
Questions to ask before you sign.
- Will you use poison inside? (Ask them not to.) - 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?
Rodents by the numbers.
Around Pasadena, ask any provider to show you the entry points and the plan before you compare numbers. Around Pasadena, those three findings — species, entry points, and scale — are what a quote should be built on, not a regional average. Around Pasadena, what actually matters is a walk-through: where the droppings are, how the rodents are getting in, and how large the colony is. National surveys set rough expectations but cannot diagnose one house.
What affects the price
- Number of entry points found during inspection.
- Whether sheds, garages or other outbuildings are included.
- Materials used for sealing: mesh, sheet metal, mortar.
- Mice versus rats; rats take longer and cost more.
- Follow-up visits included versus billed separately.
- Sewer line inspection if rats are entering underground.
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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
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 Pasadena
Pasadena only gets about 21 inches of rain a year, so local rodents look for water: drip lines, pet bowls and leaky hose bibs. Winter lows average around 46°F in Pasadena, so there's little pressure to move indoors, and activity stays steady. In denser parts of Pasadena, rats travel along alleys, fences and utility lines, so neighbors often share the problem.
Local research
Rodents in Pasadena, CA: what the public record shows
Before you compare quotes, it helps to know which rodents actually live in California, when they are busiest around Pasadena, and what the state figures look like. Everything below links to the agency or university page it came from.
Rodenticide restriction
Bromadiolone, brodifacoum, difethialone, diphacinone, chlorophacinone and warfarin cannot be applied in most areas; bromethalin, cholecalciferol and zinc phosphide remain.
UC IPMGap a rat can squeeze under a door
Roof rats travel 300+ feet for food.
UC IPMRodent species recorded in California
- 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 Pasadena
Rats active year-round; check periodically.
California's rodenticide law pushes work toward trapping and exclusion.
Rules that apply in California
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: CDC National Notifiable Diseases Surveillance System; Pest Notes: Rats; CDC; Pest Notes: House Mouse; Hantavirus. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep rodents away
- Seal the gap where the garage slab meets the wall.
- Declutter garages and attics to remove nesting cover.
- Inspect vehicle engine bays if parked near fields or woods.
- Seal every gap larger than a quarter inch with metal mesh.
- Move compost bins away from the house and use closed models.
- Install brush or rubber door sweeps on exterior doors.
After sealing, a few monitors or unset traps left along the walls tell you whether anything is still getting in before you hear it again.Did you know?
Around Pasadena, rats are strong swimmers and can tread water for a long time, which is why they sometimes travel sewer lines.
A mouse's heart beats around 500 times a minute.
Questions people ask
Are rats a bigger problem than mice?
Usually. Rats are bigger, chew more, and avoid new traps for days. Around Pasadena, roof rats often nest in attics, so check the roofline too.
Are snap traps better than poison?
Indoors, usually yes. Traps let you confirm the catch and remove it. Poisoned rodents can die inside walls and smell for weeks. Bait belongs in locked stations outside.
What does a rodent inspection involve?
The inspector checks the outside walls, roofline, vents and utility gaps. Inside, they look at the kitchen, attic, garage and under sinks. You should get a list of entry points.
Do ultrasonic repellers work?
Not reliably. Rodents get used to the sound within days. It doesn't pass through walls either. Sealing and trapping work better.
Do I need to replace attic insulation?
Only if it's heavily soiled or flattened by nesting. Light activity can often be cleaned up. Ask the inspector to show you before you agree to replacement.
Is one mouse in the house a sign of an infestation?
Not necessarily. It deserves a look. One mouse is the most common story: 37% of U.S. homeowners in the 2022 NPMA/Harris Poll reported a single rodent at some point, though a lone sighting doesn't rule out others behind the walls.
Do wealthier homes get fewer mice and rats?
Not according to homeowner surveys. Around Pasadena, in the National Pest Management Association's (NPMA) September 2022 Harris Poll of more than 1,300 U.S. homeowners, 52% of those earning $100,000 or more said they had ever had a rodent problem, slightly above the 49% for homeowners overall. Before work starts in Pasadena, ask how many visits are included and what happens if the rodents come back.
Are rodents a problem in Pasadena?
They're common here, as almost everywhere. Roof rats are also common in the area.
Sources (5)
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