Which District Handles Rats and Mosquitoes Where You Live?

Why is it so hard to know which agency handles rats and mosquitoes?

Because vector control in the Bay Area is split across counties, special districts and city health departments, each with its own boundaries and its own list of services. A town can sit inside one district for mosquitoes and another arrangement for rats. The only reliable way to know is to search your own address.

Most people expect one number to call. Instead the area around San Francisco Bay is a patchwork. Some counties have a single district that covers the whole county. Others have a county program for some pests and a separate abatement district for mosquitoes. Some cities run their own health department work. The boundaries do not follow the ones you use for mail, schools or garbage pickup.

A short rule of thumb: a district that inspects is not the same as one that treats. Several of the agencies below inspect and advise but do not do pest control on private property. That distinction decides whether you need a private company, so we keep coming back to it.

What does each district do and not do?

San Mateo County's district inspects for rats and mice for free but does not treat private property. Marin-Sonoma's covers mosquitoes, rats, yellow jackets, midges and ticks. Alameda County inspects for rats except in Berkeley. San Francisco's health department runs a complaint-based rodent program. Gaps are marked in the table.

The table below is the heart of this guide. Read the right-hand column as carefully as the middle one, because what an agency does not do is what tells you when to call a private company. Where we write not confirmed, we mean we did not find a source, not that no service exists.

What does San Mateo County's district do for people in Daly City, South San Francisco and the peninsula?

San Mateo County Mosquito and Vector Control District serves the whole county, so Daly City, Brisbane, South San Francisco, San Bruno, Pacifica, Millbrae and Burlingame all fall inside its service. It offers free residential rat and mouse inspections with a report, often within a business day, but does not treat private property.

The district is based in Burlingame and describes its service as county-wide. That is why we can say, with some confidence, that residents of Daly City, Brisbane, South San Francisco, San Bruno, Pacifica, Millbrae and Burlingame are served. We did not see city-specific detail for any of them, so we cannot tell you, for instance, whether a particular neighbourhood gets different response times.

The free inspection is the useful part. A technician inspects the outside of the home for entry points and writes a detailed report of suggested repairs and the materials to use. The typical wait we saw was the next business day. That is quick, and it costs nothing, which makes it a good first step.

The limit is just as important: the district does not treat private property, and its staff do not trap rodents or seal holes. The repairs, the trapping and the cleanup are yours to arrange, which is where a private company comes in. The district will re-inspect after you or a company has done the repairs, and the report can be handed to that company.

The district's technicians also cannot trap or exclude wildlife on private property. If what you have is a raccoon or a skunk rather than a rat, read our guide on who to call for wildlife.

What about Marin, and what does the Marin-Sonoma district handle?

The Marin-Sonoma Mosquito and Vector Control District covers two counties and handles mosquitoes, rats, yellow jackets, midges and ticks. Residents can call for rodent advice or an inspection. Its yellowjacket service covers in-ground nests only, and its services come at no added cost to residents.

This district's name tells you the geography: Marin and Sonoma counties. That covers the Marin towns in our service area, including Sausalito, Mill Valley, Corte Madera, Larkspur, Greenbrae, Kentfield and Belvedere and Tiburon.

Its list of pests is wider than a typical vector district: mosquitoes, rats, yellow jackets, midges and ticks. For rats, residents may call for advice or to schedule an inspection, which the district describes as rodent exclusion consultations. Its service pages do not say it sets traps or applies bait, so do not expect treatment; a private company does that. The district is funded through property taxes, so these services come at no additional cost to residents.

Yellowjackets show the does-and-does-not line clearly: the district's service covers in-ground nests only. Aerial nests and nests inside structures are not covered, which is a job for a private company, such as wasp and yellow jacket removal. One news report also noted calls rose 85 percent in a wet-winter surge, a reminder that demand can stretch any agency.

For mosquito issues around standing water, the district is the agency to look up first. For a rat in your own wall, you may still need a private company. See rat control for what that involves.

What happens in Alameda County, and what about Berkeley and the other East Bay cities?

Alameda County's vector control mission includes insects and rodents, and it does rat site inspections everywhere except Berkeley. We could not confirm which agency serves Berkeley, Albany, El Cerrito, Richmond or San Pablo, or whether the county's separate mosquito abatement district covers the same area. Search your address.

Here the gaps are bigger, and we want to be direct about them. What is sourced: the county's vector control program lists both insects and rodents in its mission and does rat site inspections. What is also sourced: those inspections do not extend to Berkeley. That is all we have, and it tells you where the county program stops, not where the next one begins.

We could not confirm which agency serves Berkeley, Albany, El Cerrito, Richmond or San Pablo. El Cerrito, Richmond and San Pablo lie in Contra Costa County, and Albany and Berkeley in Alameda County, but county lines are not district lines, and we are not going to guess. We also could not confirm whether the Alameda County Mosquito Abatement District covers the same ground as county vector control.

What to do in the meantime: search your own address plus the words vector control or mosquito abatement, and read the service area on the district's page. If a page does not clearly name your city, treat that as no answer.

What does the City and County of San Francisco do about rodents, and who does mosquito work?

The San Francisco Department of Public Health names Norway rats, roof rats and house mice as the main urban rodents. Its guidance says complaints go through 311, which routes them to Environmental Health, and that a residential owner or manager must investigate a report within 72 hours. Who does mosquito work inside the city is not confirmed here.

San Francisco is both a city and a county, which is part of why it does not fit the district model. The health department's guidance says Norway rats are found virtually everywhere people live and gravitate to places with many hiding places and easy access to food. Its pages say rodent complaints go through 311, which records them and routes them to Environmental Health. The department recommends pest services licensed by the San Francisco County Agricultural Commissioner that use IPM principles, and a residential owner or manager must investigate a report of pest activity within 72 hours. Garbage is a major attractant.

We could not confirm the current phone number, the exact 311 steps or whether a fine applies, and the department's pages themselves say its rodent help has moved to a newer sf.gov page, so treat this as the department's guidance rather than today's contact route. We also could not confirm which agency does mosquito work inside the City of San Francisco; if you suspect standing water is breeding mosquitoes, search the city's website for your address. If you would rather start with a private company now, San Francisco Pest Control can pass your call to an independent local one at any hour, and a technician can come the same day when one is free.

How should you use this guide to find the right office for your address?

Match your county in the table, then search your own address on the agency's site to confirm it serves you. Use a free inspection where one exists, treat a missing answer as a reason to ask, and call a private company for treatment when the district does not treat private property.

Start with the county. If you live in San Mateo County, the district covers you, and a free inspection is available for rats and mice. If you live in Marin, the Marin-Sonoma district is your starting point. In Alameda County, the county program does rat inspections except in Berkeley. In San Francisco, the Department of Public Health handles rodents, with the limits described above.

Next, confirm it for your address. District boundaries, service lists and request forms live on each agency's own website, and those pages are kept current in a way a guide like this cannot be. Search for your address with the words vector control, then read the service list. If the agency does not clearly serve your city, assume it does not until you hear otherwise.

Then decide what you need. A free inspection and report is a good start for rodents. A treatment, a sealing job, an attic cleanup or a wildlife question needs someone else. For rodents, rodent exclusion covers sealing the entry points, and mosquito control describes the private-company side of that work.

• Find your county, then search your address plus vector control.
• Read the service list: inspect, advise, treat, or none of these.
• Use a free inspection where one exists.
• Hire a private company for treatment, sealing and cleanup.
• Keep notes and reports for the next call.