Information About Rats

General Information

The roof rat (Rattus rattus) is a major problem-causing species in Orange County.  This agile rat is 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. To see a video of a rat eating dog food, click here.

Disease

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.  County residents are fortunate because there have been no outbreaks of plague in recent history.  The potential of such outbreaks could increase if rat populations are allowed to increase unchecked.

Murine typhus is another rat-borne disease that exists in certain areas of Orange County.  This disease, like plague, can be transmitted by rat fleas.  Roof rats also may be involved with the transmission of a variety of filth diseases in areas having poor sanitation.

Recognizing Roof Rat Activity

The Homeowner should be alert for these signs of roof rat activity:

• Damaged, partially eaten oranges, avocados, or other fruits. To see a video of fruits eaten by rats, click here.

• Broken snail shells under bushes, on fences, or near nesting sites.
• Signs of gnawing on plastic, wood, or rubber materials.

• Greasy rub marks caused by rats’ oily fur coming in repeated contact with painted surfaces or wooden beams.