Common throughout California, yet rarely mentioned in real estate sections,rodent pests are usually discussed only in hushed tones. Despite the factthat many people are in denial, these scurrying creatures are permanentdenizens of even our nicest, priciest neighborhoods, including Piedmontand Orinda.

A respected, experienced local home inspector told me that 80 per centof the homes he inspects show evidence of rodent activity in the basement,crawl space or attic. A majority of homeowners and buyers with whom I speak,however, are surprised to learn of the issue. They are not able to identifythe three most common rodents, nor do they know how to deal with them.

Mice and rats evoke a variety of negative responses, from annoyanceto fear and loathing. You may think, or hope, you will never come in contactwith one of these pests, but think again. Since they are so widely found,it is important to at least be aware of some basic information about them.

Rodents like large families

Our friends once had an episode with a marauding house mouse. Afterchewing some foam from their sofa, he (or she) disappeared, never to beheard from again. This was fortunate because, depending on whether youare talking about rats or mice, they can produce up to eight litters peryear with as many as 12 per litter.

Home sweet home

Mice usually live in fields, but would love to move into a cozy building- or your home. This is especially true in winter. In a house, they occupywalls, cabinets, closets and furniture.

When you hear the word "rat," it is probably the Norway rat you arepicturing. Burrowing and digging is how they try to enter our homes. Sincethey cannot dig up through concrete, a slab over the soil in the basementor crawl space of a house provides one type of rat-proofing. Another favoriteform of entry is through a broken sewer line and up into your plumbing.

A sound you may think is a squirrel or cat running across your roofmay, in fact, be your new upstairs neighbor - a roof rat. Nimble climbers,they can easily scale trees, telephone poles and lines, wires, pipes andwall studs, entering your home through holes as small as one-half inch.

Roof rats are excellent leapers. They can jump vertically 36", horizontally48", and can bound eight feet from a tree to a house. Along with trees,they nest in shrubs, ivy, woodpiles, sewers and storm drains. These creatureshave become more prevalent in our area in the past 15 years.

Signs of a break-in

Droppings are an obvious clue, but there are other signals of an uninvitedpresence. Rats are continually gnawing. Their teeth can grow more thanfive inches a year; they need to gnaw to shorten and sharpen them.

Roof rats have been known to cause fires by chewing through electricalwiring. One busy roof rat, by scratching, clawing and scrambling, can soundlike an army. They tend to be most active at night. If you hear soundsfrom your attic, do not ignore them.

Other indicators are outdoor paths or runways where grass is beatendown; oil or grease smudge marks in runways; urine stains and odors. Oneclassic sign is an agitated or excited cat or dog. This could be your firstwarning of a rodent invasion.

Evicting the critters

Rats leave scent trails that may last for years. A couple we know successfullyeradicated roof rats only to have them return three years later. Mice cancome and go through holes no bigger than a pencil eraser. Before you canget rid of these pesky rodents, you must acknowledge the problem. Onceyou have done that, you have a number of options.

Vector control. Call your local city or county vector controlagency. They will send out a technician who will help you ascertain thesituation and give you advice.

Pest control operator. If you contact a private contractor,make sure it is someone with experience who understands what to look forand what to do. You want to know who your visitor is, where it is gettingin and how to give it the boot. Keep in mind these animals are intelligentand generally have more than one way in and out of your home.

Improve sanitation. Check for any food or garbage accessibleto the rodents. Cat or dog food left outdoors is an invitation for infestation.

Remove vegetation. Ivy, high grass and bushes close to thehouse attract rodents and can provide nesting sites. Cut them back.

Traps or baits. If you use a trap, cage or bait, you can expecteither a live rodent that must now be disposed of, or a foul-smelling deadone. Neither choice is attractive.

Cats. Some indoor/outdoor cats are effective hunters and willkeep rodents at bay; others are just pussycats.

Rat-proofing. Even if holes are too small, mice and rats areincredibly adept at enlarging them by chewing and scratching. Preventivetechniques include using materials such as sheet metal, steel wool, metalscreening, or concrete to:

- block openings around and in air vents, exhaust fans, sewer and water
- pipes and cables
- repair foundation and/or exterior cracks or holes
- seal roof openings and repair soffits
- pour concrete over earthen floors in basements and/or crawl spaces

Final thoughts

Rodent pests are a natural, albeit unpleasant, aspect of our lives.Where there are people, mice and rats abound, unless you move to Antarctica.

Notwithstanding state law, which requires sellers to fully discloseproblems about their property, I rarely see sellers mention past or presentrodent activity. Discomfort or embarrassment prevents some people fromconfronting this issue.

If you have, or think you might have rodents in your house, accept realityand do something about it soon. Waiting will definitely multiply your difficulties.Better still, do some preventive maintenance now.

Rodent research was derived from various Internet articles and myinterview of Jim Rounds, a local pest control operator and trapper since1957. Thanks to home inspector John Brogan for his assistance.