Pest Control in San Francisco, CA

Who deals with rats in San Francisco, the city or me?

It depends on whose land the rats are on. The San Francisco Department of Public Health names three important urban rodents: Norway rats, roof rats and house mice. Its program is proactive and complaint-based, and it identifies the species first and then surveys for whatever is attracting them. Garbage is described as a major attractant.

On the ownership question, the department's approach is that private owners deal with infestations on their own land, while the city mainly handles public property. It can inspect private buildings and food facilities when vermin are reported. We cannot summarise the current complaint steps, any fines or tenant and landlord duties here, so check sf.gov for the live rules.

If the rats are in your building, a technician can work from the same logic the city uses: work out which species it is, then find the food, shelter and entry points. Our guide to rats and mice in San Francisco sets out who handles what, and rat control covers the visit itself.

How do rats get into old San Francisco buildings?

UC IPM says Norway rats burrow along foundations and under rubbish or woodpiles, while roof rats climb and nest above ground in shrubs and dense vegetation, then move indoors into attics, walls, false ceilings and cabinets. A building with a mixed history, such as a Victorian with a rear addition, a converted garage and a century of cable and pipe work, offers both routes.

The usual advice from UC IPM is to seal any opening wider than 1/4 inch with steel wool, wire screen or sheet metal, and to keep garbage in tight lids. Where lids are shared by a whole building, the weak point is often the habits of a dozen households rather than any one wall. Rodent exclusion is the sealing side of the job, and mouse control covers the smaller animal that fits through the smaller gap.

Park edges add a wrinkle. The National Park Service species list for the Presidio includes the roof rat, so homes bordering large planted areas may see climbers as well as ground-level Norway rats.

When do termites swarm in San Francisco, and what does it mean for an old house?

UC IPM reports that western subterranean termites swarm in calm, sunny periods right after the first autumn rains, and that this is especially pronounced in the Bay Area. In a city with dry summers and wet winters, that first soaking after the dry months is the cue to watch for wings on a windowsill or a pile of discarded wings near a door.

A swarm shows that termites are in the area, not that your house is infested, and it does not say how big a colony is. Because so many San Francisco buildings are older and have wood close to soil, a termite inspection is a sensible response to either swarmers or a pending sale. Our guide to old San Francisco houses and termite inspections explains the paperwork side, and subterranean termite control covers treatment.

Drywood termites live in dry above-ground wood such as attics, fascia and trim, which older rooflines supply in quantity. They are a separate problem with a separate approach, covered under drywood termite control.

What does sea fog do to a San Francisco house?

Summer here is dry on paper, but sea fog keeps mornings overcast and the air damp, and winter brings the rain. Exterior wood such as window sills, porch rails, trim and decks spends a lot of the year damp. Wood that stays damp decays and also becomes easier for insects to use.

A technician looking at dry rot and wood damage checks where water sits: below windows, at the base of stairs, around downspouts and where trim meets masonry. Our guide to fog, damp air and wood in coastal Bay Area homes goes through what an inspection looks at.

What do restaurants and apartment buildings change about pest work here?

A dense city puts food businesses and homes in the same buildings, often with a restaurant at street level and apartments overhead. Roaches and mice move through shared walls, pipe chases and garbage areas, so a problem in one kitchen can show up two floors up. Commercial pest control is built around that reality: a technician looks at the whole building envelope, the waste area and the delivery doors, not just the room where the complaint came from.

The health department says it can inspect private buildings and food facilities when vermin are reported. A written record of what was found and what was done is useful if that ever happens. For tenants in shared buildings, bed bug treatment and cockroach control usually work best when the manager arranges access to neighbouring units too.