If you have been setting traps for more than two weeks with no reduction in catch rates, the entry points are still open. Show Me Pest Control's Portola Valley exclusion assessment locates every access point and seals it with material mice and rats cannot chew through.
Why Trapping Alone Fails
A rodent protocol that produces a permanent result addresses inputs before outputs. This is how we approach every job in Portola Valley.
Our technicians approach every property like a puzzle - finding not just the obvious entry points but the gaps that have been open for years undetected. The resulting written map documents every opening, its location on the exterior, and the material used to seal it permanently.
The materials matter as much as the locations. We use steel mesh, copper wool, and commercial exclusion sealants - not the consumer products that mice return through by the following spring. Every material is matched to the gap type and the exposure it will face.
Evidence mapping before trap placement is what converts trapping from a guessing game into a predictable clearance process. Runway smear marks identify the active travel corridors. Droppings distribution maps the harborage zone. Station placement follows the evidence - not a default pattern.
We return after treatment to check every exclusion point, review bait station activity logs, and confirm the interior population has cleared. Follow-up is not optional - it is how we verify the work actually held.
The Population Math
Rat reproduction follows a similar pattern but at a different scale. Norway rats produce 4 to 6 litters per year with 8 to 12 pups per litter. Roof rats - more common in warmer parts of CA - produce 5 to 8 litters per year. Both species require larger entry gaps than mice (rats need approximately 1/2 inch vs. the 1/4 inch that mice can pass through), but both enter through the same categories of structural vulnerability: plumbing penetrations, damaged vent screens, gaps at the roofline and fascia, and foundation cracks. The entry point categories are the same; the sealing materials and methods scale to the size of the animal and the structural gap.
The most common trap placement mistake is working from a default pattern rather than evidence. Placing snap traps along every wall in a kitchen produces far lower catch rates than placing them on the specific runways identified by smear marks, at the specific corners where dropping density indicates concentration, and near the specific harborage locations identified by nesting material or insulation disturbance. Evidence-based placement converts trapping from a shotgun approach into a targeted clearance process. This is why the assessment precedes any station placement - the evidence determines the strategy, not a standard protocol that ignores what the property shows.
Traps filling but the problem persisting in Portola Valley?
Call +1-866-315-0243. An entry point assessment in Portola Valley locates every gap in your structure and seals it with rodent-resistant material.
The 14 entry points that most homeowners never find are not exotic or difficult to locate once you know what to look for. They include: gaps around plumbing penetrations in the cabinet undersides (a 1-inch pipe run through a 1.5-inch hole leaves a 1/4-inch annular gap on each side - more than enough for a mouse), HVAC duct penetrations through the basement ceiling or crawl space floor, weep holes in brick veneer (intentional architectural openings that are unintentionally perfect mouse entries), the gap above the garage door track where the top seal meets the framing, the space between the sill plate and the foundation in older construction where sill plate shrinkage creates gaps, roof-fascia separation at the gutter line where repeated thermal cycling opens joints, and dryer vent terminations with worn or missing flap dampers. Most of these gaps are in locations that are never visually surveyed by the homeowner - under the sink, in the crawl space, at the roofline. Our assessment methodology is specifically designed to reach these locations because that is where the entries are.
Attic rodent infestations present a specific set of considerations that differentiate them from standard interior treatment. Contaminated attic insulation - insulation saturated with rodent urine and droppings over a sustained infestation period - is a health and structural concern that requires remediation beyond the rodent control treatment itself. Roof rats are the primary species in attic infestations in warmer parts of CA; Norway rats in the basement or crawl space is the more common pattern in northern areas. The entry point categories for attic infestations focus on the roofline: fascia gaps, broken or missing roof vent screens, soffit-fascia separations, and construction gaps at chimney flashing. Commercial rodent programs add a documentation layer not required in residential treatment: service logs, catch records, station maps, and trend reports are standard requirements for food service establishments operating under health department oversight in Portola Valley and CA. Show Me Pest Control provides full program documentation for commercial accounts as a standard component of every service agreement.
Services Provided

Comprehensive entry assessment produces a written map of every structural opening - the document that makes the exclusion work verifiable and the follow-up inspection efficient.
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Steel mesh, copper wool, and rodent-rated sealants at every identified penetration. This is the work that changes the math - sealing inputs so every trap catch becomes a permanent net reduction.
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Evidence-mapped bait station placement following the exclusion work. Active runways, droppings distribution, and nesting evidence determine where stations go - not a default grid pattern.
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Roofline and foundation entry assessment, snap trap and bait station placement in confined access spaces, and recommendations on insulation remediation where rodent contamination has occurred.
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Commercial rodent programs in Portola Valley with full documentation packages: station maps, service logs, catch records, and trend analysis formatted for health department compliance.
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The follow-up visit is when the work is confirmed. Exclusion points re-inspected, station data reviewed, and clearance documented when both confirm zero active population.
Call to ScheduleThe Process
We assess the infestation by phone - species, affected areas, duration, and any previous treatment history - before scheduling.
Every gap, penetration, and structural opening documented. The written map is the foundation for the exclusion work and the follow-up verification.
Exclusion is completed before trapping begins. With entries sealed, station placement follows the evidence map for maximum efficiency.
Scheduled follow-up re-inspects every exclusion point, reviews bait station data, and confirms population clearance before the account is closed.
Client Results in Portola Valley
Four months, two mice a week, zero improvement. The assessment identified 9 entry points - the two behind the refrigerator water line alone were eye-opening. Exclusion sealed all 9. Not a single catch in three weeks after that. The problem was the open entries, not the traps.
11 entry points along the old sill plate gap - that was the answer. The previous contractor said the house just had mice. Show Me Pest Control found 11 openings that a proper entry assessment was designed to find. Sealed them all. No rodent activity the following winter. The house does not just have mice. It had gaps.
The prior national chain documented the dishwasher drain gap in their reports but never sealed it. Show Me Pest Control sealed it in the same visit as the assessment. Zero activity in the follow-up period. Eighteen months of monthly billing for a problem that had a single identified cause that nobody addressed.
Common Questions
The most common reason rodents return after sealing in Portola Valley is that the entries you found were not all the entries. Gaps under the kitchen sink at the plumbing penetrations, weep holes in brick, dryer vents with missing dampers, and sill plate gaps in older construction are rarely found by self-inspection. Our assessment methodology is designed to reach these specific locations - because that is where the entries are. We also use rodent-resistant materials rather than consumer foam, which rodents chew through in one season.
We use steel mesh, copper wool, and commercial-grade rodent exclusion sealants - materials that rodents cannot chew through, as opposed to expanding foam alone, which mice and rats readily gnaw through within one season. The material used at each entry point is matched to the gap size, the location, and the exposure: steel mesh for larger structural openings and plumbing penetrations, copper wool packed into small gaps and crevices, and commercial exclusion caulk to seal and finish. The written entry map we produce documents the material used at every location so the follow-up inspection can verify that each seal remains intact.
We use tamper-resistant bait stations that require a specific mechanical action to open - designed so that children and pets cannot access the bait material. Stations are placed in locations not accessible to children or pets where possible: under appliances, inside cabinet bases, along wall runs behind furniture. For homes with specific concerns about bait safety, snap trap-only protocols are also available. We discuss placement locations and safety considerations with every client before treatment and adjust the approach based on your household situation - call +1-866-315-0243 to discuss your specific setup in Portola Valley.
Most residential rodent cases in Portola Valley follow a 2-visit structure: exclusion and station placement, then follow-up 2-3 weeks later to verify and confirm clearance. With exclusion complete, the interior population clears predictably. Commercial properties run on monthly service schedules with documentation. We give you a timeline estimate based on your specific property during the initial phone conversation.
Yes. Attic rodent treatment involves roofline entry assessment - fascia gaps, broken vent screens, soffit separations - and trap placement in confined spaces. Crawl space treatment focuses on foundation-level entry assessment and station placement in low-clearance areas. Both require specific assessment methodology that standard interior inspection does not cover. We also advise on insulation remediation for attics with significant contamination from extended infestation. Call to schedule in Portola Valley.
The exclusion-first principle is the same for both, but the specifics differ. Mice can enter through a 1/4-inch gap; rats require a 1/2-inch opening. Entry point categories differ accordingly - the gaps that require steel mesh for rats are often sealed with copper wool for mice. Rat runway evidence (smear marks, droppings size, gnaw marks) differs visually from mouse evidence, affecting station placement. Norway rats concentrate in basements and crawl spaces; roof rats concentrate in attics. Bait formulations and trap types differ between species. We identify the species during the assessment and adjust the exclusion material selection, station placement strategy, and trap type to match the specific animal. A protocol designed for mice applied to a Norway rat infestation will produce incomplete results for the same reason that misidentified species in cockroach treatment produces incomplete results - wrong protocol for the specific pest.
If you have been catching mice every week with no improvement, the entry points are still open. Call +1-866-315-0243 to schedule an entry point assessment in Portola Valley - the step that ends the treadmill.
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