Cockroach Elimination
Cockroach Control in San Mateo, CA
German Cockroaches · American Cockroaches · Commercial & Residential
Cockroach infestations are among the most difficult to eliminate with over-the-counter products — German cockroaches in particular develop resistance to pyrethroid sprays within a single generation. 101 Exterminators uses a combination of gel baits, insect growth regulators (IGRs), and targeted void treatments to eliminate active colonies and prevent re-infestation. Serving San Mateo and surrounding San Mateo County.
Warning Signs
Signs You Need Cockroaches Service in San Mateo
Species-specific treatment using gel baits, insect growth regulators (IGRs), and targeted void treatments. Gel bait is placed directly at harborage sites — behind refrigerators, under sinks, inside wall voids — where cockroaches consume and transfer it to others in the colony. IGRs prevent juvenile cockroaches from reaching reproductive maturity, collapsing the population within 2–4 weeks. Commercial kitchen programs include written documentation of conducive conditions for health inspection compliance.
Live cockroaches seen during the day — indicates a large infestation overflowing harborage sites
Cockroach droppings (small, dark, pepper-like pellets) under sinks, behind appliances, or in cabinets
Egg cases (oothecae) — small, brown, capsule-shaped casings — in sheltered areas
Musty or oily odor in kitchen, bathroom, or utility areas
Shed cockroach skins near harborage sites
Cockroach activity visible in commercial kitchen equipment, drain areas, or food storage
How It Works
Our Cockroaches Process in San Mateo
Every job follows the same methodical approach — no shortcuts, no guesswork. Here is what to expect when you work with us in San Mateo.
Inspection & Species ID
We identify the cockroach species and locate all harborage sites — behind refrigerators, under sinks, inside wall voids, and in any warm, dark area near moisture or food. Species identification determines the correct bait and treatment approach.
Bait Application
Gel bait is placed at harborage sites in quantities cockroaches will find and consume. Bait is formulated to be transferred between individuals — a single fed cockroach will infect others in the colony, reaching the full population.
IGR Treatment
Insect Growth Regulators (IGRs) prevent juvenile cockroaches from reaching reproductive maturity, collapsing the population within 2–4 weeks even without direct contact with adults.
Exclusion & Prevention
We identify and seal gaps around plumbing penetrations, appliances, and wall voids that provide harborage. For commercial kitchens, we provide a written report of conducive conditions for health inspection compliance.
Why 101 Exterminators
Cockroaches You Can Count On in San Mateo
Bait-Based Treatment
Gel bait reaches cockroaches that surface sprays cannot — inside appliances, wall voids, and harborage sites that sprays would scatter.
Health Inspection Ready
Our commercial cockroach programs are documented and meet California health department expectations for food-handling facilities.
IGR Included
Insect Growth Regulators prevent resistant survivors from reproducing, ensuring the population collapses rather than rebounds.
No Surface Spray Scattering
Broad spray applications push cockroaches into new harborage areas. Our targeted approach eliminates colonies in place.
Common Questions
Cockroach Control FAQs for San Mateo
Why won't spray can products eliminate German cockroaches?
German cockroaches have developed resistance to pyrethroids — the active ingredient in most OTC sprays — through decades of widespread use. Spraying also scatters the population, spreading cockroaches to new areas rather than eliminating them. Professional gel bait and IGR treatments work by different mechanisms that cockroaches have not developed resistance to.
How long does cockroach treatment take to work?
Visible cockroach activity typically decreases within 3–7 days of initial treatment. Full population collapse takes 2–4 weeks as IGRs prevent juvenile cockroaches from reaching reproductive maturity. A follow-up service at 3–4 weeks confirms elimination and addresses any remaining harborage areas.
Do I need to empty my kitchen cabinets before treatment?
For gel bait treatments, you do not need to empty cabinets — the bait is placed in small amounts in harborage areas, not sprayed on surfaces. We will advise on any specific preparation needed based on your home's layout and the extent of infestation.
Are cockroaches a health risk?
Yes. Cockroaches carry and transmit Salmonella, E. coli, and other pathogens on their bodies and in their droppings. Their shed skins and fecal matter are significant allergens linked to asthma onset in children. A German cockroach infestation in a kitchen is a genuine food safety risk, not just an aesthetic problem.
Can cockroaches survive between treatments?
A single female German cockroach can produce 300–400 offspring in her lifetime. Untreated survivors will rebuild the population. This is why our program includes IGRs and a follow-up service — to ensure no surviving reproductive females can repopulate the area.
Cockroach Control · San Mateo
Free Cockroaches Inspection in San Mateo
CA licensed and insured. Written estimate before any work begins. Same-day response available for urgent situations in San Mateo.