
Rodent Management
Rodent Control in San Mateo, CA
101 Exterminators does rodent control in San Mateo exclusion-first — find the openings, seal them, then trap — California licensed under SPCB Lic. #9119. The older San Mateo neighborhoods carry a mature street-tree canopy, and roof rats (Rattus rattus) use it to reach rooflines without ever crossing open ground. That changes where an inspection starts.
Home maintenance
How do you keep rats and mice out of a San Mateo home?
Take away food and cover, then close the gaps. The City of San Mateo’s rodent program, run with the county vector district, asks residents to secure garbage, pick fruit, bring in pet food and bird feeders overnight, trim overgrown plants and close access points. Creek-side neighborhoods and old tree canopy make that list matter more here.

Pick fruit and clear windfall
Citrus, plums and loquats in older San Mateo yards feed roof rats for months. Pick fruit as it ripens and clear what falls, especially on lots near San Mateo Creek and Laurel Creek.
Cut limbs back from the roof
San Mateo Park’s eucalyptus, redwood and pine and the city’s mature street trees reach many rooflines. Trim branches that touch or hang over the roof so rats can’t step from tree to shingle.
Bring pet food and bird feeders in at night
The city lists both as rodent attractants. Feed pets indoors or pick up bowls at dusk, and take feeders in overnight or hang them where seed can’t pile up below.
Seal gaps with metal, not foam
Close openings around pipes, vents and the garage door with hardware cloth, sheet metal or mortar. Rats chew through foam and plastic, and older homes have settled enough to open new gaps.
Keep the garbage enclosure shut
In apartment buildings and downtown mixed-use blocks, Norway rats live off trash rooms. Keep lids closed, report broken bins to the manager, and don’t leave bags beside a full container.
Ask for the county’s exterior inspection
The San Mateo County Mosquito and Vector Control District inspects the outside of a property for rodents and reports what it finds. Use its list of openings as a repair checklist.
When to do it
Trimming and sealing in late summer and early fall, before the November rains push rodents indoors.
Maintenance guidance: City of San Mateo, Public Works rodent control
Warning Signs
When to Ask About Rodent Control in San Mateo
Our program combines three components: (1) Exclusion — sealing gaps in foundations, pipe penetrations, vents, and roof eaves using hardware cloth, copper mesh, foam sealant, and sheet metal as appropriate. (2) Trapping — placement and monitoring of snap traps, live traps, and glue boards in active areas. (3) Exterior bait stations — tamper-resistant bait stations positioned along perimeter rodent runways for ongoing population management.
Droppings along walls, in cabinets, behind appliances, or in attic insulation
Gnaw marks on wiring, wood, plastic pipes, or food packaging
Grease marks along walls or baseboards — oil from rodent fur rubbed repeatedly on surfaces
Nesting materials (shredded paper, insulation, fabric) in hidden locations
Scratching or scurrying sounds in walls, ceilings, or under floors at night
Burrows in landscaping, mulch beds, or under concrete slabs
Citrus or avocado fruits with bite marks — a classic roof rat indicator
Pet acting alert at walls or cabinets when no visible cause exists
How It Works
What to Expect from Rodent Control in San Mateo
Tell us where you hear activity or find droppings, and whether you can see a possible entry point. We can then plan where to check first.
Inspection & Runway Mapping
We identify gnaw marks, runways, burrows, droppings, and grease trails to map rodent activity throughout the property — interior and exterior.
Exclusion
We seal all discovered entry points with durable materials appropriate to the opening — hardware cloth, copper mesh, sheet metal flashing, or foam sealant for smaller gaps.
Trapping & Bait Placement
Interior snap traps and exterior tamper-resistant bait stations are positioned along active runways. We monitor and service these on a schedule until activity ceases.
Follow-Up & Monitoring
We return to clear traps, replenish bait, check exclusion work, and confirm that the population has been eliminated before closing out the service.
Why 101 Exterminators
Why Choose 101 Exterminators for Rodent Control in San Mateo
Exclusion-First Methodology
Without sealing entry points, any rodent removed will simply be replaced by another. We seal the structure before or concurrent with trapping — not as an afterthought.
No Unmonitored Poison Bait Indoors
We do not place loose rodenticide indoors where rodents can carry it to walls and die inaccessibly. Interior work uses traps with daily monitoring during active treatment.
Regional Species Knowledge
Norway rats, roof rats, and deer mice behave differently and require different approaches. We identify the species present before selecting treatment methods.
Sanitation Recommendations
After resolving an infestation, we advise on harborage removal, vegetation management, and food storage to prevent reinfestation — not just a repeat service call.
Common Questions
Rodent Control FAQs for San Mateo
I hear scratching in the ceiling of my San Mateo Park house — rats or squirrels?
Ceiling noise after dark is usually roof rats; daytime noise is usually squirrels. Roof rats run at dusk and again before dawn, and in the older San Mateo neighborhoods with heavy street-tree canopy they get to the roof by branch rather than by wall. Check the attic access for droppings or a greasy rub mark, and check whether any limb overhangs the roof. Trimming that limb removes the route, but the entry still has to be sealed.
Do houses near Marina Lagoon and Seal Slough get a different rat problem?
They get Norway rats more often than roof rats. Norway rats burrow along levee banks, riprap and storm drains, and the bayshore edge at Marina Lagoon and Seal Slough is continuous habitat for them. In Shoreview and North Shoreview they usually enter low — a broken foundation vent, a gap at the sewer lateral, a crawl-space door that no longer seats in its frame. On those addresses we start under the floor, not in the attic.
Can rodents get into a San Mateo house built on a slab with no crawl space?
Yes — a slab just moves the entry points upward. Rodents use the garage door seal, utility and plumbing penetrations at the slab edge, dryer vents, and the roof-to-wall transitions common on the low-slope roofs in the Highlands and 19th Avenue Park. On slab construction we spend most of the inspection on the garage, the roofline and the utility chases, because there is no sub-area to check.
Local Pest Pressure
Common Pests We Treat in San Mateo
Every area has its own pest profile shaped by climate, housing, and geography. These are the pests we see and treat most often in San Mateo — tap any one to learn how to identify it and what treatment involves.
Rodent Control · San Mateo
Schedule Service in San Mateo
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