Rodents

Side view of an all-black icon of a rat. The rat's tail is longer than its body (it is a roof rat).

The District provides rodent inspections to help residents reduce rodent issues in and around their houses. If you would like a rodent inspection, please fill out a service request.

Rats need many of the same things we do: food to eat, water to drink, a safe place to live, and the company of their families. Unfortunately, they sometimes find those resources in our neighborhoods. Commensal rodents, such as roof rats, Norway rats, and house mice, have been associated with people for hundreds of years. They live on our food and waste products and inhabit our buildings.

Having rats doesn’t mean a neighborhood is dirty or poorly-kept. Most neighborhoods have at least some rats, and any neighborhood can find itself with a large infestation. Rodents can cause serious damage to structures, equipment, furniture and utilities, and may spread a wide variety of diseases, including leptospirosis, trichinosis, hantavirus, rickettsial diseases, and bacterial food poisoning.

Rodent fact sheet

Side black silhouettes of four animals. An opossum, a mouse, a rat, and a squirrel

Rodent Identification

Both wild and commensal rodents may infest homes and other structures, especially in rural areas. These are a few of the most common rodent species that you may see San Mateo County.

Rodent Prevention and Control

The District does NOT conduct rodent control on private property, but can assist homeowners and tenants with identifying and solving rodent infestations. We can:

Three people in white Tyvek suits are around a table covered in white plastic. One person holds a small brown mouse while the other person looks on.

Rodent Surveillance and Data

Rodents can spread many diseases. These diseases can be spread to humans directly, through handling of rodents, through contact with rodent feces, urine, or saliva, or through rodent bites. Diseases carried by rodents can also be spread to humans indirectly, through ticks, mites, or fleas that have fed on an infected rodent.

Sideview of a mouse. The mouse is mostly dark brown, but the belly of the mouse is white. The mouse has light pink feet, large black eyes, and long white whiskers.

Hantavirus

Hantavirus is the common name for hantavirus pulmonary syndrome (abbreviated as HPS), which is caused by inhaling particulates infected with Sin Nombre virus. Sin Nombre virus is carried by native deer mice (Peromyscus maniculatus) and shed in their urine, feces, or saliva.

A grey and light brown squirrel stands partially emerged from a hole in the ground.

Plague

Plague is a bacterial disease that can be fatal if left untreated. There are three forms of the disease:

May contain: rat, animal, mammal, and rodent

FAQS about Rodents

There are many different kinds of rodents in San Mateo County but the most common nuisance rodents are house mice, roof rats, and Norway rats. You can learn more about these on our rodent identification page.

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