Rodent control in San Mateo, CA
Droppings, gnaw marks or scratching in the walls can point to rats or mice. A pest professional can help find how they get into your San Mateo home.
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How rats and mice get in
Rats and mice come inside for food, water and shelter. They fit through very small openings. The San Mateo County Mosquito and Vector Control District says any gap greater than a quarter inch could let a rodent in.
The District also says that trapping and baiting only control rodents for a short time if no rodent proofing is done. Rodent proofing means sealing the openings rodents use. The District advises doing it before trapping or baiting.
The District can inspect homes for signs of rodents and give a written report on what it finds. It does not trap or bait for residents. For that work it points people to a licensed pest control company.
Signs of rats and mice
- Droppings in cupboards, drawers, along walls or in the garage.
- Gnaw marks on food packages, wood, wires or plastic.
- Scratching or running sounds in walls, ceilings or the attic, often at night.
- Dark, greasy rub marks along walls, pipes or beams where rodents travel.
- Shredded paper, cloth or insulation gathered into a nest.
- Pet food or birdseed that keeps going missing.
- Burrows by the foundation or under a deck.
What a rodent inspection covers
Rodent work starts with finding the way in. A pest professional can look at these areas with you.
- Where rodents are active, both inside and outside.
- Openings around pipes, vents, doors, roof lines and the foundation.
- Food and shelter outside, such as fruit trees, ivy, wood piles and pet food.
- Which openings need sealing, what material will be used and who does that work.
- Whether traps will be used, where they go and how often they get checked.
- What happens after the openings are sealed, and whether a return visit is part of the plan.
Ways to keep rodents out
Sealing comes first. These steps also make a home less inviting.
- Look closely for gaps wider than a quarter inch and get them sealed.
- Store food, pet food and birdseed in sealed containers.
- Keep trash in bins with tight lids.
- Pick up fallen fruit and trim plants back from the roof and walls.
- Move clutter and wood piles away from the house.
- Fix leaks that give rodents water.
Found droppings or a nest? Ask a pest professional or the District for guidance before you clean them up.
Questions about rodent control
Does it matter if I have rats or mice?
Yes. Rats and mice use different spaces, and the plan for each can differ. Tell the pest professional about the droppings, sounds and any animal you saw. That helps sort it out.
Should I set out rodent bait myself?
Talk with a professional first. The District says baiting and trapping give only short term control when openings are not sealed. Sealing the way in comes first.
I have bites I cannot explain. Could it be related?
The District notes that rat mites are sometimes a problem during a rat infestation. If you have unexplained bites, see a doctor and mention the rodent problem.
Can the county help with rodents?
The San Mateo County Mosquito and Vector Control District can inspect for signs of rodents and give advice. It does not trap or bait for individual homes or businesses.
Call for help with rodent control
Have your notes and a photo ready, then call.
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Also seeing roaches near food? Read about cockroach control.
Back to pest control in San Mateo, CA
Pest guidance on this page is based on San Mateo County Mosquito and Vector Control District: Rodent Prevention and Control. Those statements belong to that source.