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May contain: mammal, animal, rat, and rodent

The roof rat (Rattus rattus) is agile and slender, with a tail longer than its head and body. Roof rats frequently enter buildings and move about neighborhoods by using utility lines and fences as runways. They prefer to feed on wild bird seed, pet food and many of the fruits and nuts (including those that people do not eat) commonly found in residential backyards.

Certain landscape plants are used as homes by roof rats and other flea-carrying animals.


Many plants native to California are good choices for landscape use and do not encourage rats. For a list of suggested native plants, click here

What we do 

When an Orange County Mosquito and Vector Control District Inspector comes out to a residence for a rodent service request, the Inspector will assess the situation to see what is the best way to handle the rodent problem. Every house and every situation is different and needs to be treated as such. Some measures that might work in your neighbor's yard will not necessarily work in your yard. 

When the Inspector comes to your house he/ she will inspect the exterior of the home and the yard to point out potential attractants to rodents and possible entry points the rats may be entering through.

Depending on the situation, removal of these attractants may be all a homeowner needs to do to take care of the rodent problem. 

Please Note: The Rat Program will be seasonally suspended from July 1st to November 25th due to increased mosquito workload.

Rat Education Program  

The District has a multifaceted roof rat education program that includes:

  • Presentations and participation in local outreach events to educate the public about rodent control practices.
  • The creation and distribution of training DVDs for homeowners to educate them about rats, how to reduce rat populations, and how to rat-proof their residence.
  • Extensive literature on rat control, rat trapping, common entry points for rats on houses and mobile homes, vegetation that attracts rats, alternative ground cover that rats are not attracted to, how to rat-proof homes, and many other publications are available in print and electronically.
  • Inspectors educate homeowners and neighborhood groups about rats on their property and how to remove sources that would attract rats onto the property. 
  • Staff attends local and national educational conferences to learn about advances in rat control techniques, products, and other measures to better educate and protect the public from rats and the potential harm they can cause.


The most common pathway of exposure to rodent-borne diseases is through consumption of food or water contaminated with rodent feces and urine. 

Rats and rat nests can be infested with biting mites and fleas. Mites and fleas can transmit illnesses to humans. 

Rats and their fleas are capable of transmitting a variety of human diseases. Among the diseases transmitted by rats, bubonic plague is perhaps the best known and the most serious.  There have been no outbreaks of plague in Orange County in recent history. The potential of such outbreaks could increase if rat populations are allowed to increase unchecked.