Frequently Asked Questions (FAQ)

General information

Frequently Asked Questions about the District

Are you part of the county government?

No. San Mateo County Mosquito and Vector Control District is an independent special district.

What is an independent special district?

You can learn about independent special districts here.

General information

Frequently Asked Questions about District Services

How can I identify your vector control technicians?

Our vector control technicians wear a uniform with the District name clearly visible on the shoulder patches, and upon request can show their District badge and ID. Laboratory staff may work out of uniform when conducting disease surveillance activities, but will have a District badge and ID.

To get to know the technician(s) and other staff who work in your area, visit our staff profile pages.

General information

Questions about Mosquito Biology

What attracts mosquitoes to me?

Mosquitoes find you by warmth, smell, and the carbon dioxide (CO2) on your breath. Some people are more attractive to mosquitoes than others; this is mostly genetic.

General information

Frequently Asked Questions about Larval Mosquito Control

How much water do mosquitoes need to breed?

Even very small amounts of water can provide enough space for mosquito larvae. Some mosquito species need as little as a bottle cap full of water to reproduce!

How long does it take for mosquitoes to breed?

Under the right conditions, it can take as little as a week for mosquito larvae to emerge as adults. In general, warmer weather means faster development.

General information

Frequently Asked Questions about Helicopter Larvicide Treatments

What areas do you treat by helicopter?

The District currently uses a helicopter to treat three freshwater marshes: Annex Lake (Stanford property), Mills Field (SFO property), and Sharp Park Golf Course.

At each of these locations, only the water is treated.

When do helicopter treatments occur?

Helicopter treatments are scheduled as needed. You can find upcoming treatments listed on our calendar. We conduct an average of four treatments per year.

General information

Frequently Asked Questions about Adult Mosquito Control

Why are you fogging?

If West Nile virus is detected in the community, the District’s initial response will be to intensify its efforts to locate and reduce mosquito breeding sites, increase its levels of larviciding in those areas in which West Nile virus has been found, and increase trapping of adult mosquitoes for disease testing. Reducing the adult mosquito population with pesticides (adulticides) registered by the US Environmental Protection Agency (EPA) will be done if necessary to prevent human illness or to suppress a heavy nuisance infestation of mosquitoes.

West Nile virus

Frequently Asked Questions about West Nile Virus

What is West Nile virus?

West Nile Virus is a mosquito-borne virus that originated in Africa. It first appeared in the United States in 1999 and it moved West until it reached California in 2003. It is present throughout the year, although illness is often associated with peaks during hot summer months.

Blog post

Frequently Asked Questions and Answers about Zika Virus and Invasive Aedes in San Mateo County

 Zika virus has been in the news often recently, and District staff members have received many questions from the family, friends, members of the public, and the media. Here are a few of the most common questions, and their answers:

General information

Frequently Asked Questions about Ticks

How can I protect myself from ticks?

  • When outdoors in areas where there may be ticks, wear long pants and sleeves. Don’t wear shorts, sleeveless shirts, or sandals. Tuck pants into socks or boots, and shirts into pants. Light-colored clothing makes it easier to see ticks before they attach to the skin.
  • The insect repellents that work for mosquitoes are effective against ticks. Look for formulas containing DEET. These should be applied according to the label instructions only.

Frequently Asked Questions about Rodents

What kind of rodents do we have in San Mateo County?

The most common nuisance rodents in San Mateo County are house mice and roof rats. You can learn more about these on our rodent identification page.

Other rodent species found in San Mateo County include deer mice and wood rats. These rarely cause nuisance to humans.


Frequently Asked Questions about Wildlife

What kind of wildlife do we have in San Mateo County?

Common wildlife included raccoons, skunks, opossums, squirrels, deer, rats and mice, and coyotes.

General information

Frequently Asked Questions about Yellow Jackets

What’s the difference between yellow jackets and bees?

Yellow jackets feed on other insects as well as nectar, while bees feed only on nectar. Bees can only sting once while yellowjackets can sting multiple times. Yellowjackets have black and yellow stripes and shiny bodies while bees are fuzzy and brownish. Bees typically build hives in hollow trees high above the ground. Their hives contain wax combs. Yellowjackets build round paper nests either under the ground or hanging from tree branches. Bees produce honey and feed on nectar and pollen from flowers.