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FAQS about Rodents

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

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.

If you live near open space, agriculture, or a park that has a lot of native habitat, you may also encounter native mice, wood rats (also called pack rats), voles, ground squirrels, tree squirrels, or chipmunks.

What diseases do rodents carry? 

Rodents can carry a variety of diseases including hantavirus and plague. While these diseases are rare, it is generally not recommended to spent a lot of time around wild rodents. You can learn ways to rodent-proof your home.

Why do I still have rodents if I keep my property clean? 

A clean property really helps to discourage unwelcome visitors, but rodents are very clever and can find numerous ways to gain access. They will be attracted to any source of food, water or shelter, so check your property very carefully to ensure that all garbage, kitchen scraps, pet food, fallen fruit from trees, or any other source of food attractant is sealed away. Talk to your neighbors and make sure they know to rodent-proof their property, too. Rodents can gain access to your home through any hole the size of your thumb, so make sure to inspect your property every year for any sign of holes or gaps. You can learn how to do this.

If you need help inspecting your property and are a San Mateo County resident, please call the main District line at (650) 344-8592 and request a free rodent inspection. We cannot do repairs but we can help you figure out what’s attracting the rodents and how they’re getting inside.

How can I get rid of rodents on my property? 

You can find tips and tricks for rodent-proofing your property HERE. If you need additional help and guidance and are a San Mateo County resident, call the main District line at (650) 344-8592 and request a free rodent inspection. One of our technicians can inspect your property for access points and provide suggestions for keeping rodents out. The District does not do any repair work or rodent baiting and removal. You will need to contract with a private pest control operator for that service.

How do I know what kind of rodents are causing my problem? 

You can find rodent identification information HERE. If you’re still not sure and are a San Mateo County resident, call the main District line at (650) 344-8592 one of our technicians can provide a free inspection to help you figure out what kind of rodents are causing your problem.

What are the signs of rodent infestation? 

You can find detailed information about detecting rodent activity HERE, but some signs of rodent infestation may include:

  • back rub marks on the edge of ledges or entering holes
  • rodent droppings
  • gnawing damage
  • gnaw marks on fallen fruit
  • rodent holes or burrows
  • live or dead rodents
  • urine, feces, or rotten meat odors
  • scrabbling or scratching noises in the ceiling or walls

Regular inspection for signs of rodent infestation will help you identify any problems early, saving you time and money.

What should I do if I think my neighbor is the source of my rodent problem? 

First, talk to your neighbor. They may not be aware of the problem, or may not know how to resolve it. Share information with them and encourage them to inspect their own property or request a rodent inspection from the District.

District staff cannot write citations or force your neighbor to remove rodent attractants from their property. Unless there is a public health risk, residents cannot be forced to conduct rodent-proofing on their own property. If you believe the situation represents a threat to human health or safety, you may contact your city’s code enforcement department.

Can you trap and remove rodents on my property? 

Sorry, we cannot do rodent-proofing, repair access points, or trap/bait rodents on private property. However, we can give you the information you need to do this yourself. We also cannot recommend specific pest control operators (PCOs), but we can give you tips on what to look for. A PCO should be honest, transparent about costs, tell you what they would like to do and get your permission before they do it. They should be up-to-date on the latest technology and information and use an integrative pest management (IPM) approach. You can read about what IPM is HERE.

We also recommend that PCOs be licensed through the California Department of Pesticide Regulation with specific certifications depending on their specialization. More information on PCO licensing can be found HERE.



Page last reviewed: August 12, 2021

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