FAQs

General FAQ

Monday through Friday, 8:00 a.m. to 12:00 and 12:30 to 4:30 p.m.

Call us at our office and we will get a technician out to help you. Our phone number is: 707-553-9610.

Usually we respond within 24 to 48 hours to your call (except for weekends).

You can come by our office between the hours of  8:00 am and 3:00 pm  (Monday to Friday) or by appointment, to pick up mosquito fish. Please call our office at (707) 553-9610 to confirm availability prior to coming.

  • There is no charge for obtaining mosquitofish from the District.
  • Please bring a 5-gallon bucket with you to carry them in.

In addition, our mosquito fish are usually available from April 15 to October 15 at the following locations. Please call your preferred pick-up location first to confirm availability.

Van Winden’s Garden Center
1805 Pueblo Avenue
Napa, CA 94588
(707) 255 – 8400

St. Helena Central Valley Builder’s Supply
1100 Vintage Avenue
St. Helena, CA 94574
(707) 963-3622

We provide mosquito fish to the citizens of Napa County free of charge.

A vector is any animal or insect that can spread disease to humans or otherwise be of a nuisance.  The Napa County Mosquito Abatement District primarily deals with the following vectors: mosquitoes, yellowjackets,  ticks, and rodents.

Call the West Nile Virus hotline (a toll-free number) at 877-968-2473. This number is sponsored by the California Department of Health Services and is the agency responsible for the collection and testing of dead birds for West Nile Virus. Please note that only fresh-dead birds, with no known cause of death, are the birds being tested for West Nile Virus.

You can contact the District at 707-553-9610.

A list of the pesticides used by the District can be found on our Pesticide Summary page. The pesticides we use are designed to be target specific and cause the least environmental disruption possible when used at the label rates dictated by State and Federal law.

A list of the pesticides used by the District can be found on our Pesticide Summary page. The pesticides we use are designed to be target specific and cause the least environmental disruption possible when used at the label rates dictated by State and Federal law.  For more information you can see our Technical Summary on Pesticides page or go to the following links:

Learn as much as you can about mosquitoes,  yellowjackets, ticks, and rodents, then keep the areas around your home free of standing water, debris and overgrown vegetation. If you need information or assistance contact us and we will be happy to help you.

Mosquito FAQ

  1. Reduce outdoor activities during peak mosquito feeding periods.
  2. Wear long pants and long sleeved shirts.
  3. If you must be outside during peak mosquito activity apply insect repellents.
  1. Avoid areas known to be infested with mosquitoes.
  2. Wear long sleeved clothing and long pants.
  3. Keep your yard free of debris and standing water.
  4. Examine trees on property for holes, cavities or crotches, which can hold water.
  5. Empty, turn upside down or throw away containers that collect water, such as cans, buckets and old tires.
  6. Use approved repellents on legs and exposed skin. Follow the manufacturer’s instructions carefully.
  7. Make sure pets and farm animals receive regular veterinary care and are properly vaccinated.
  1. Examine trees on property for holes, cavities or crotches, which can hold water.
  2. Empty, turn upside down or throw away containers that collect water, such as cans, buckets and old tires.
  3. Make sure pets regularly see their veterinarian and are taking a heartworm preventative medication.

Some things you can do to protect yourself, family and pets from mosquitoes include:

  1. Talk with your physician about possible treatments.
  2. Avoid areas known to be infested with mosquitoes.
  3. Wear long sleeved clothing and long pants.
  4. Use approved repellents on legs and exposed skin. Follow the manufacturer’s instructions carefully.
  5. Wash bite with soap and water.
  6. Apply cold cloth for swelling.
  7. Watch for secondary infection.
  1. Keep your yard free of debris and standing water.
  2. Examine trees on property for holes, cavities or crotches, which can hold water.
  3. Empty, turn upside down or throw away containers that collect water, such as cans, buckets and old tires.
  4. Mosquitoes are present year round. Contact your local Mosquito and Vector Control District for assistance.

There are 20 mosquito species found in Napa County, ten of which are bothersome to humans and their pets. Some species can carry diseases and therefore all mosquitoes should be identified. Mosquitoes occur year round.

Yellowjacket FAQ

  1. Avoid the area! Yellowjackets rarely sting if they are left alone
  2. Keep children and pets away from the nest.
  3. Do not disturb or try to remove the nest.
  4. Avoid loud sounds and vibrations near the nest.
  5. Even though your neighbor might suggest it, DO NOT pour gasoline or other flammable products into the hole.
  6. Notify your local Mosquito Abatement District, a pest control company or local governmental authorities for identification and removal.
  1. Leave the area quickly!
  2. Cover your face
  3. Use clothes to protect your eyes and mouth from yellowjackets.
  4. Yellowjacket attacks can last until the victim vacates the area
  5. Seek basic first aid if necessary
  6. Watch for allergic reactions
  1. Wash the sting with soap and water.
  2. Apply antihistamine or anti-itch medication, ice or cold cloth, or meat tenderizer to the bite for swelling and pain.
  3. Watch for swelling or hypersensitive reaction.
  4. For allergic reactions seek medical care immediately. Watch for difficulty with breathing or dizziness.
  5. If stung in the mouth or throat seek immediate medical care.
  1. Avoid wearing perfumes or other scented products such as sunscreen, deodorants, cosmetics, hairsprays, and brightly colored and patterned clothes.
  2. Avoid going barefoot, especially in vegetation.
  3. Avoid cooking and eating outdoors where yellowjackets are present.
  4. Do not swat at yellowjackets.
  5. Do not drink soft drinks from an open container. Keep lids on drinks.
  6. Keep foods covered. Close or cover containers of meat or sugary foods.
  7. Check food before you put it in your mouth.
  8. Place all food waste in tightly covered garbage cans.
  9. Place traps far away from eating and gathering areas.
  10. Keep garbage cans away from picnic areas.
  11. Eliminate water sources like dripping outdoor faucets or standing pools of water.
  12. Contact your local Mosquito and Vector Control District for assistance with the elimination of these pests.
Yellowjacket nests can be difficult to identify as many of them appear to be nothing more than a hole in the ground. Yellowjacket nests can frequently be found along ditches, paths and fence lines. You can find a photo and additional information about yellowjackets here.

Many people mistake an umbrella wasp nest for a yellowjacket nest. Umbrella wasps commonly build their nests under eves of homes and in wall areas. Their nests have the shape of an inverted umbrella thereby giving them their name. They can also be known as paper wasps. You can find a photo and additional information about umbrella wasps here

Rodent FAQ

Call Napa County Mosquito Abatement District for identification and advice. Our phone number is: 707-553-9610.

Call Napa County Mosquito Abatement District for identification and advice. Our phone number is: 707-553-9610.

Hantaviruses are a group of viruses that may be carried by some rodents. Some hantaviruses can cause a rare but deadly disease called hantavirus pulmonary syndrome (HPS). For more information go to our Summary of Rodent Diseases page or the Centers for Disease Control.

Do the following things to minimize risk of hantavirus infection:
  • Before occupying abandoned or usused cabins, open them up to air out. Inspect for rodents and do not use cabins if you find signs of rodent infestation.
  • If you sleep outdoors, check potential campsites for rodent droppings and burrows.
  • Do not disturb rodents, burrows or dens.
  • Avoid sleeping near woodpiles or garbage areas that may be frequented by rodents.
  • Avoid sleeping on bare ground, use a mat or elevated cots if they are available.
  • Store foods in rodent-proof containers and promptly discard, bury, or burn all garbage.
When cleaning rodent contaminated areas:
  • avoid creating aerosols and stirring up dust
  • use rubber gloves and a mask
  • apply household disenfectants at maximum recommended concentration to dead rodents, rodent droppings, nests, contaminated traps and surrounding areas and allow for at least 15 minutes contact time before removal.
  • clean the affected areas with paper towels or a mop, do not sweep or vacuum
  • double bag the disinfectant-soaked rodent(s) and clean-up material securely in plastic bags and seal tightly
  • before removing gloves, wash gloved hands in disinfectant, and then in soap and water. Throughly wash hands with soap and water after removing gloves. Dispose of gloves and clean-up materials with other household waste.
For more information go to our Summary of Rodent Diseases page or the Centers for Disease Control.

Arenavirus is a rodent transmitted viral disease. Arenavirus infections are relatively common in humans in some areas of the world and can cause severe illnesses. The arenaviruses are divided into two groups: the New World or Tacaribe complex and the Old World or LCM/Lassa complex. For more information go to our Summary of Rodent Diseases page or the Centers for Disease Control.

For information go to our Summary of Rodent Diseases page or the Centers for Disease Control.

Plague is a disease involving rodents and their fleas which transfer the infection to various animals including humans. For more information go to our Summary of Rodent Diseases page or the Centers for Disease Control.

For information go to our Summary of Rodent Diseases page or the Centers for Disease Control.