◈ Homepage — https://acvcsd.org/Skip to content Translate... Chinese (Simplified) English Hindi Spanish Vietnamese Search Search (510) 567-6800 Request Service Programs & Services Open Programs & Services FAQs Resources About Us Serving Alameda County Residents, Property Owners & Property Managers Alameda County Vector Control Services Alameda County Vector Control Services District is a Division within the Environmental Health Department, which is one of four departments of the Alameda County Health. Our District assists the 1.6 million residents of Alameda County with vector-related issues and is funded primarily through benefit assessment taxes. Request Service (510) 567-6800 What are Vectors? A vector is a living organism that transmits an infectious agent from an infected animal to a human or another animal. Vectors are frequently arthropods such as fleas, lice, ticks, and flies. But rodents and wildlife, such as rats and skunks can also vector disease to people and animals. Rodents Invertebrates Wildlife Disease Surveillance Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. 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Only adult female mosquitoes bite and transmit disease. More Information Vector Significance Vector Control Services What can the public do? Photo Gallery Vector Significance Mosquitoes are responsible for transmitting several diseases, including malaria, dengue, yellow fever, dog heartworm, West Nile Virus, Chikungunya, and Zika viruses In the Bay Area, West Nile Virus poses the greatest risk Mosquitoes are also a biting nuisance, and can cause unpleasant allergic reactions Vector Control Services Alameda County Vector Control does not provide mosquito related services Please contact Alameda County Mosquito Abatement District at (510) 783-7744 or visit their website . What can the public do? Limit outdoor activities during dawn and dusk when mosquitoes are most active Clean out and empty stagnant water sources on your property, such as cans, jars, plant saucers and gutters Minimize exposed skin and consider the use of mosquito repellents when outdoor in areas with mosquito activity Resources Alameda County Mosquito Abatement District Mosquitoes Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Ticks | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Invertebrates / Ticks Ticks Ticks are small parasitic arachnids that feed off the blood of mammals, birds, reptiles, and amphibians. They undergo four life stages: egg, larva, nymph, and adult, and a blood meal is required to advance to the next developmental stage. There are three common ticks that bite humans in Alameda County: The Western Black Legged tick ( Ixodes pacificus ), the Pacific Coast tick ( Dermacentor occidentalis ), and the American Dog tick ( Dermacentor similis ). Adult ticks look for hosts by perching themselves on overhanging grasses and branches at the edges of trails. Immature ticks are most often found in leaf litter, on wood piles, or mossy rocks. More Information Vector Significance Vector Control Services What can the public do? Photo Gallery Vector Significance Ticks can transmit several infectious diseases that affect humans The occurrence of tick-borne illnesses in humans is increasing worldwide The Western black legged tick is the main vector of Lyme disease The Pacific Coast tick is the main vector of Pacific Coast tick fever and tularemia The American dog tick is the main vector of Rocky Mountain spotted fever and tularemia Vector Control Services Vector Control can identify the species of tick Vector Control can make recommendations on how to limit exposure to ticks in and around your property Vector Control Biologists routinely conduct tick-borne pathogen surveillance in regional parks and open spaces throughout the County Alameda County Vector Control District does not test ticks that have been removed from humans or pets The following agencies and companies will test these ticks for a fee: Solano County Public Health Laboratory Solano County – Tick Testing (Lyme Disease) Santa Clara County Public Health Department Test ticks for Lyme disease | Public Health | County of Santa Clara Sonoma County Public Health Regional Laboratory Lyme Organism in Ticks Bay Area Lyme Foundation Tick Testing – Bay Area Lyme Foundation Connecticut Veterinary Medical Diagnostic Laboratory How to Submit a Tick | Connecticut Veterinary Medical Diagnostic Laboratory IGenex Tick Test | Send Ticks for Testing | IGeneX TickCheck TickCheck Tick Testing – Laboratory Tick Testing Services for Lyme & Tick-Borne Diseases Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service What can the public do? Always hike in the center of the trail Avoid walking in areas with heavy leaf litter Use insect repellent before you go hiking In areas with high tick populations, do not sit on logs or rocks Check yourself, pets, and gear for ticks immediately after hiking If bitten by a tick, removing it within 24 to 36 hours will help reduce the risk of pathogen transmission Keep the removed tick in alcohol so it can be identified by Vector Control staff or a professional entomologist Resources A Guide to Ticks Common Ticks in Alameda County Lyme Disease and Other Tick-borne Diseases Lyme Disease in California (ucanr.edu) What to Do After a Tick Bite (cdc.gov) Ticks Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Cockroaches | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Invertebrates / Cockroaches Cockroaches Cockroaches are an ancient group of insects numbering over 4,600 species, with about 30 associated with humans. Cockroaches have a flattened appearance, long antennae with a downward bent head and their color can range from light to dark brown, to black. Mature female cockroaches produce an egg case which can be found at the tip of the abdomen. In Alameda County, the most common species are the German cockroach, the Turkestan cockroach, and the Oriental cockroach. More Information Vector Significance Vector Control Services What can the public do? Types of Cockroaches Vector Significance The German cockroach is the most common cockroach found indoors They readily consume human food and can contaminate it with harmful pathogens For some individuals, debris from cockroaches, such as feces and shed “skin” may trigger allergic reactions Turkestan and Oriental cockroaches are species that prefer to live outdoors, but can accidentally invade homes, causing distress for residents Outdoor cockroach species are not considered to be significant vectors of disease-causing pathogens Vector Control Services Vector Control Services can: Identify the cockroach species Identify areas of harborage and attractants Advise methods of control and exclusion Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service What can the public do? Most pest species of cockroaches are controlled successfully with gel baits For indoor German cockroach infestations, reducing clutter and cleaning kitchen surfaces are advised Larger infestations may require the services of a pest control professional For outdoor cockroaches, closing gaps underneath doors (including garage doors) with weather stripping and sealing cracks around pipes and foundations is recommended In addition, keeping the foundation free of excess vegetation will reduce harborage Resources Cockroaches Management Guidelines (UC IPM) Types of Cockroaches German Cockroaches This troublesome pest is found in homes, apartment buildings, warehouses and commercial kitchens. They prefer hiding in warm, humid and dark areas. Large infestations create allergens that may trigger asthma in children or other allergic reactions. They may contaminate food and eating utensils with pathogens such as Staphylococcus and Streptococcus. Guide to German Cockroaches Oriental & Turkestan Cockroaches Both species share similar habits and are often found in water meter boxes, drains, or wood piles. They prefer to live outdoors and may accidentally find their way inside residences. Fortunately, neither poses a risk to public health. Guide to Other Cockroaches American Cockroaches In Alameda County, American cockroaches are mostly limited to sewer systems. They can be found in ground floors of buildings if there are damaged pipes or openings. While they do not commonly infest indoors in Alameda County, they can transmit bacteria such as Salmonella when they get in contact with human or animal feces. Guide to American Cockroaches Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Rodents | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Rodents Rodents Rodents are mammals that possess a single pair of growing incisors (front teeth) in both the upper and lower jaws. They can carry pathogens in their urine and feces and harbor vectors such as fleas, mites, and lice. Vector Control focuses on both commensal rodents (those that live in close proximity to humans) and wild rodents. District biologists perform inspections of properties and make recommendations to help relieve residents of their rodent problem. More Information Control & Prevention Types of Rodents Guide to Rodents Control & Prevention​ Removing rodent food sources and shelter through cultural and environmental modifications is essential in rodent prevention and control. Rodent-proofing structures is the only solution which provides long term control and ensures rodents will not be able to enter a building. Poor sanitation and the presence of garbage and rubbish around a structure are contributing factors to rodent infestations and should also be considered when addressing a rodent problem. These three domestic rodents have different habits and behaviors. Thus, it is very important to properly identify which rodent species is the source of damage or nuisance. If you are experiencing rodent problems, please call our District or submit an on-line request for service. Our staff will conduct on-site inspection and evaluation of the conditions promoting any rodent problems, and make recommendations for control and prevention. Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service Types of Rodents Commensal Rodents Other Rodents Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Skunks | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Wildlife / Skunks Skunks Skunks are medium sized mammals that are commonly found in urban, suburban, and rural areas throughout the Americas. In Alameda County, striped skunks ( Mephitis mephitis ) are by far the most common species, with rare sightings of the spotted skunk in more rural parts of the county. Skunks are known for their ability to spray a foul-smelling liquid as a defense against predators. They are poor climbers but excellent diggers. More Information Vector Significance Vector Control Services What can the public do? Photo Gallery Vector Significance They are an important rabies vector in Alameda County Fleas are commonly found on skunks and can reach high numbers in skunk dens These same flea species readily bite humans and can infest domestic pets and spread disease They have a noxious spray that they use in self-defense The spray is not toxic but can cause irritation, temporary blindness and trouble breathing Vector Control Services Biologists can help determine where the skunk is living on the property and assist residents in identifying attractants and closing access points. If necessary, help remove the animal from the property. Determine if the animal’s behavior is that of a healthy animal. Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service What can the public do? Remove food sources that can attract skunks such as pet food, spilled birdseed, and fallen fruit Remove standing water from your yard Check your property for open crawl space vents, openings beneath decks, or burrows Focus on blocking entrances at ground level and use fencing to keep skunks from entering your yard If you or your pet is sprayed by a skunk, use a mixture of 1 quart hydrogen peroxide, a quarter cup of baking soda and 1 teaspoon of dish soap to remove the smell If you see a dead skunk, please contact Animal Control . Resources A Guide to Skunks Dealing with Skunks (unl.edu) Skunks – Solutions to Common Problems (psu.edu) Skunks (ucanr.edu) Skunks Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Rabies | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Disease Surveillance / Rabies Rabies Rabies exists throughout Alameda County and is a fatal viral disease for both animals and humans. Rabies is passed through the saliva of infected animals, typically through a bite. In Alameda County, dogs, cats, bats, skunks, and horses have been infected with rabies and bats are typically the main reservoirs. Occasionally, rabies can be transmitted if the saliva of an infected animal gets into a fresh scratch, breaks in the skin, or contacts a human’s eyes, mouth or nose. The Alameda County Vector Control District acts as the liaison between animal control agencies, the County Public Health Lab, and the local community to coordinate the rabies surveillance program. Our District transports specimens for rabies testing to the Public Health lab and assists the County Public Health Department with rabies case investigations. In the event of a positive rabid bat, vector control biologists will inspect homes and businesses for signs of bat roosting and/or entry points into the structure. In response to a positive rabid bat, vector control biologists perform a survey of the local neighborhood, distributes rabies alert memos, and educates members of the public. If you think you may have been exposed to rabies, seek medical attention immediately Resources Rabies (cdc.gov) Rabies (cdph.ca.gov) Forms Rabies Testing Lab Slip Rabies Exemption Packet Animal Bite Incident and Rabies Exposure Report Form (REDCap) Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Fleas | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Invertebrates / Fleas Fleas Fleas are small (1/10th -1/8th inch), vertically flattened insects that infest and move about the hairs of warm-blooded animals. They are wingless and cannot fly, but they have spring-like legs that allow them to jump long distances relative to their body size. Fleas feed on the blood of dogs, cats, and other warm-blooded animals including humans. However, most flea species prefer specific non-human hosts The cat flea, Ctenocephalides felis, is the most common flea found in homes and feeds primarily on cats, dogs, raccoons and opossums Another flea, Pulex simulans , prefers skunks and other wildlife, but will readily feed on humans and can also invade homes More Information Vector Significance Vector Control Services What can the public do? Photo Gallery Vector Significance Certain types of fleas, including the Cat flea and Oriental rat flea, have the potential to transmit diseases after feeding on infected hosts or when infected flea feces are scratched into a wound. These diseases and conditions include: Plague Tularemia Murine typhus Tapeworm infections Allergic dermatitis in humans and pets While fleas are common in Alameda County, flea-borne diseases are very rare. Vector Control Services Vector Control can: Provide inspections of properties (homes, schools, commercial) to confirm presence of fleas or other biting insects Identify species of fleas and potential harborage for fleas and flea-carrying animals Determine whether wildlife is currently living on the property Assist with eviction of wildlife living under or within a structure Provide recommendations regarding flea infestations and nuisance wildlife Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service What can the public do? For indoor infestations: Check household pets for excessive scratching or biting, and the presence of fleas in fur Manage fleas on household pets with veterinarian recommended flea control Thoroughly and regularly clean pet areas indoors and outdoors Frequent vacuuming indoors For outdoor infestations: Pesticide treatments on outdoor shaded areas where pets rest can be effective Reduce moisture and increase sunlight into the yard to “dry out” fleas Check that wildlife (including feral cats) are not living on the property Resources A Guide to Fleas How to Manage Pests (ucanr.edu) Fleas & Flea Bits (cdc.gov) Fleas Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Spiders | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Invertebrates / Spiders Spiders Spiders are arachnids, a group of arthropods that are wingless, possess eight legs, and have no antennae. Ticks and mites also belong to this group. There are approximately 50,000 known species of spiders and they are found in nearly every habitat worldwide. In the United States there are approximately 3,500 identified species of spiders. Fortunately, most spiders play a beneficial role by consuming nuisance insects that impact humans. More Information Vector Significance Vector Control Services What can the public do? Types of Spiders Vector Significance Spiders possess a venom that is used to kill and digest prey Most spiders are of little public health concern since few possess venom that will affect humans Spider bites can result in uncomfortable pain and swelling The black widow is the ONLY spider of medical importance in Alameda County This species has a powerful neurotoxic venom, and bitten individuals may require medical attention The brown recluse spider is not found in Alameda County or California All cases of bites related to brown recluse spiders in California are due to travel to the Midwest US Because brown recluse spiders are not native to California, the risk to the public is very low Vector Control Services Provide inspections of properties and give advice on how to lessen spider abundance Provide identification of spider specimens Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service What can the public do? Monitor the corners, ceiling, and door jams for the webbing/egg sac and vacuum up immediately A night-light will attract insects which attract spiders, so avoid leaving your porch light on at night, or use a motion detector sensor Plants, which provide food and harborage for insects and spiders, should be kept back from the perimeter of your living structure Keep window and door screens in good repair A monthly rinsing of eves, windows, and doors will help reduce spider populations on the exterior of your home An effective way to remove an unwanted spider from your home is to vacuum it up with the hose and wand attachment Locating and removing eggs sacs will reduce future spider populations As a last resort, pesticides may be used to control spiders Spiders Types of Spiders Western Black Widow Spider ( Latrodectus hesperus ) Females of this species have a rounded black body (½ inch) with a red hourglass on the underside of the abdomen The male black widow is smaller and has a shiny black abdomen like the female but lacks the hourglass Both sexes may have yellow and red marks on their backs in immature stages The Western black widow spider is found throughout Alameda County These spiders are shy, nocturnal, and stay hidden during daylight hours Preferred habitats include garages, attics/basements, burrows, debris, and dense vegetation Medical attention may be required if there is a reaction to a bite Guide to Spiders Brown Recluse Spider ( Loxosceles reclusa )  They are native to the Midwest United States and are not normally found in Alameda County This species is about 3/8 inches long, has a uniformly colored abdomen that varies from cream to dark brown and has a dark brown violin shape on its back The unique eye pattern consists of six eyes in pairs with a space separating the pairs All Loxosceles spiders have venom that can cause necrotic skin lesions Although these spiders are not established in Alameda County, interstate travel creates the possibility of an unwanted introduction Suspect brown recluse spiders found by County residents should be submitted to the District for identification Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Stinging Insects | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Invertebrates / Stinging Insects Stinging Insects There are several species of insects in Alameda County that can sting humans, but are considered less aggressive and/or less common than yellow jackets and honey bees. At the bottom of this page, is a list of common stinging insects in Alameda County. More Information Vector Significance Vector Control Services What can the public do? Varieties of Stinging Insects Vector Significance Although capable of stinging, these species are not known to transmit disease to humans or pets Reactions to stings can vary from short-term discomfort to substantial pain Reactions such as swelling, tenderness, and itching, to life-threatening allergic responses can occur Vector Control Services Vector control biologists can identify the species of stinging insects and help determine risk Depending on the level of public health risk, remove or treat stinging insect nests PLEASE NOTE: Insects inside buildings (walls, attics, or foundations) are not serviced by the District, and you are advised to contact a professional pest management company. Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service What can the public do? Since all the insects on this list are important pollinators, use of insecticides is discouraged unless the insects are posing an immediate threat to safety Sealing openings (cracks, holes, and gaps) can prevent nests in structures As a last resort, wasp sprays or pesticide dust may be used Varieties of Stinging Insects Yellow Jackets Yellow jackets are medium sized wasps about half an inch long. Their bodies are black with distinctive bands of bright yellow on their abdomen. They have a lance-like stinger and can sting repeatedly when attacking a perceived threat. A large nest consists of a queen and up to thousands of workers, with the nest growing in numbers as the warmer seasons progress. Most nests die off each winter and the overwintering queens begin the spring constructing a new nest and hatching a new brood of worker yellow jackets. Ground nests are most common, but they can be found in wall cavities and other void areas of a house. Some species will build an aerial nest that hangs freely from tree limbs or other high places. A Guide to Yellow Jackets How to Manage Pests (ucanr.edu) Paper Wasps The most common species in Alameda County is the European paper wasp, Polistes dominula . They are similar in appearance to yellow jackets but are larger, slimmer and have yellow legs and antennae. Unlike yellow jackets, they dangle their legs while flying. Their nests are constructed from wood pulp, hence the name “paper wasp”, and are usually found under eaves or sheltered patio areas. Paper wasps are less aggressive than yellow jackets, but they can sting. Newly forming paper wasp nests can be removed with a strong stream of water from a garden hose or knocked down using a long pole. A Guide to Paper Wasps Honey Bees The Western honeybee ( Apis mellifera ) is the most common honeybee species in the world. They are known to form large colonies containing a single reproductive female known as the “queen”. Worker bees (also females) pollinate plants and produce honey to sustain their hives throughout the cooler seasons. Honeybees play a critical role in the ecosystem by pollinating many agricultural crops and native plants. A Guide to Honey Bees Alameda County Beekeepers Association (alamedabees.org) Removing Honey Bee Swarms & Established Hives (ucanr.edu) Bumble Bees Bumble bees are larger than honeybees, measuring ¾ to one inch long and are usually fuzzy. Most species form colonies and they typically build their nest in ground cavities, but some are found in wood piles, walls, sheds, or crawl spaces. The most common species of bumblebee in Alameda County is the yellow-faced bumblebee, Bombus vosnesenskii . They can become aggressive and sting when their nests are disturbed but are docile while foraging. Please contact the Vector Control Services District and consult with one of our Biologists before deciding to destroy a bumble bee nest. A Guide to Bumble Bees Carpenter Bees Carpenter bees are similar in size to bumblebees, but less hairy. They make nests by creating tunnels in various types of wood, including structural timber, fence posts, and telephone poles. The most common species in Alameda County is the valley carpenter bee, Xylocopa sonorina . Females are completely black, and males are fuzzy and yellow. These bees are unlikely to sting unless provoked and are more docile than yellow-faced bumblebees. Carpenter bee nesting can be discouraged by painting over the wooden surfaces. Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us Commensal Rodents | Alameda County Vector Control Skip to content Search Search (510) 567-6800 Request Service Programs & Services Close Programs & Services Open Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea-borne Rickettsias Rabies Rodent-borne Disease Swimmer’s Itch Tick-borne Disease FAQs Resources About Us Menu Request Service Home / Programs & Services / Rodents / Commensal Rodents Commensal Rodents In Alameda County, the most common commensal rodents are the roof rat, the Norway rat, and the house mouse. A commensal rodent is one that lives among humans and is dependent upon them for basic survival needs. The roof rat is believed to be of Southeast Asian origin, the Norway rat is originally native to northern China, and the house mouse is native to areas of Asia and central Europe. All three of these species are now found worldwide and over millennia, have caused much distress to humans and disruption to ecosystems. In Alameda County, the Norway rat has a more restricted range than the roof rat, and the house mouse can be found countywide. More Information Vector Significance Vector Control Services What can the public do? Types of Commensal Rodents Vector Significance Rodents can transmit disease-causing pathogens through their urine and feces Rodent droppings can contaminate surfaces with pathogens such as Salmonella, Leptospira and lymphocytic choriomeningitis Rodents may act as a reservoir species for diseases such as bubonic plague and murine typhus They can also be hosts to associated ectoparasites, especially fleas and mites Fleas infected with pathogens can spread disease from rodent to rodent and rodent to human via a bite or infected fecal material Vector Control Services District Vector Control Biologists can: Identify what rodent species is present Help identify signs of rodent activity, potential entry points into structures, and possible attractants on the property Provide recommendations and education on repairs, property clean-up and proper rodent-proofing of structures Requesting Services If you are interested in our services and want to request inspection, click the button below: Request Service What can the public do? Make sure there are no openings into your home with a diameter larger than a quarter inch Seal openings with quarter-inch hardware cloth (galvanized steel wire mesh) or strong metal flashing Reduce harborage sites around your home that can attract rodents, such as dense vegetation and clutter Keep trees from touching the roof line Pick up fallen fruit and do not let it accumulate in your yard Sweep up spilled birdseed Ensure that garbage cans are tightly covered and avoid feeding pets or wildlife outdoors Types of Commensal Rodents Roof Rat ( Rattus rattus ) Compared to the Norway rat, the adult roof rat is slightly smaller with darker fur and a tail longer than its body. Roof rats have a pointed snout and larger ears and eyes. Their nests are typically found in dense vegetation or wood piles outdoors and attics and wall voids indoors. Being excellent climbers, they can easily enter structures though small openings often invading attics but are also found in subareas or wall voids. Their diet varies, but there is a preference for fruits, nuts, seeds, snails, and pet food. Guide to Roof Rats Norway Rat ( Rattus norvegicus ) Compared to the roof rats, the adult Norway rat’s body is larger with lighter colored fur. They have a blunter snout, smaller ears and eyes, and a shorter tail than the roof rats. Efficient at digging and typically nesting in underground burrows, they also colonize the sewer systems giving them the moniker “sewer rat”. Norway rats diet varies but prefers protein-rich foods such as dog food and meat. They can cause major structural damage to homes and infrastructure. Guide to Norway Rats House Mice ( Mus musculus ) The smallest of the commensal rodents, adults measure 5-to-7 inches long, including the tail, which can measure 3-to-4 inches. House mice are highly adaptable, widespread, and their fast reproductive rate makes them the most common rodent infestation in homes. Infestations are typically identified by fecal droppings and a strong urine smell. They often construct nests using shredded materials, and damage property by contaminating them with urine, feces and chewing. Mice have a varied diet but prefer grains and are consider “nibblers”. Guide to House Mice Environmental Health Department 1131 Harbor Bay Parkway, Ste. 166 Alameda, CA 94502 (510) 567-6800 View Map Programs & Services Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance Rodents Invertebrates Wildlife Disease Surveillance FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us FAQs Resources About Us Copyright ©2026 Alameda County Vector Control. All Rights Reserved. Legal / Disclaimers Designed and Developed by Denali Data Systems. Menu Request Service (510) 567-6800 Search Search Programs & Services Rodents Commensal Rodents Other Rodents Invertebrates Ants Bed Bugs Cockroaches Fleas Flies Mites Mosquitoes Spiders Stinging Insects Ticks Wildlife Bats Opossums Other Wildlife Raccoons Skunks Disease Surveillance Flea Borne Rickettsias Rabies Rodent-Borne Disease Swimmer’s Itch Tick-Borne Disease Resources FAQs About Us