Q: I have a problem with moles that are destroying my yard. They cause severe ruts and have burrowed over the yard, causing the grass to die. I have sought advice, but no one seems to have a solution. Do you have any advice on how to get rid of these pests?

A: Moles create a huge network of tunnels just beneath the surface, where they feed on grubs, earthworms and insects. They don't actually eat plants, but they damage the soil and disturb the plant root system. A single mole can damage an acre of lawn or garden.

There are numerous methods of mole control. Some are eviction methods, while others are methods of extermination.

Pouring creosote, lye, tar, mothballs or drain-flushing granules into their tunnels may drive moles to more congenial hunting grounds, such as your neighbor's yard. But these methods can also injure plants and contaminate soil. Moles prefer to dig in loose, sandy soil, so compacting the soil with a roller, mixing gravel in with it or allowing the soil to dry out will often drive moles away. But this will also leave your soil less than desirable for plant growth.

Extermination is the more standard solution to the problem. One approach is to use poison. This involves digging holes into the tunnel network and depositing poison. It takes two to three weeks, but the moles eventually will die underground. One disadvantage to poisonous bait is that moles tend to eat bugs, worms and grubs before they go after the poison. Another, more serious disadvantage is that the poison can be a hazard to other animals in the area. Poisonous smoke bombs are also available. For the bombs to work, it is necessary to put them directly in nests or in the main runways with all access holes blocked.

Trapping is the most efficient control. The easiest type of mole trap to use is a harpoon trap. To set a trap, you locate a mole tunnel and step on it from above. Then place the trap over the tunnel and push the legs of the trap into the ground over the area you have stepped on. When the mole tries to reopen the collapsed tunnel, it will trigger the trap, causing sharp tines, the "harpoons," to release and kill the mole. Because moles are more active at night, you may want to set traps out at night and take them in during the day to avoid any accidents with children or household pets.

Whatever approach you take, it is necessary to find active tunnels, many of which will be abandoned. Stomp down a few sections of tunnel, then check it the next day. If it's mounded up again, its an active tunnel, suitable for baiting or trap-setting. Traps, suitable poisons and mole bombs are usually available at garden centers and hardware stores.

Q: We are plagued by cockroaches. Do you have any recommendations on how to get rid of these pests?

A: Prevention is the key to pest control.

Clean the favorite bug hangouts regularly. These include kitchens, bathrooms or any other areas in your house that provide the dark, dampness or dust that insects love. Keep tight-fitting lids on trash containers and use disposable plastic liners. Spray containers' interiors every two weeks with surface insecticide.

Move heavy furniture and kitchen appliances once a month to clean behind and under these pieces. Remove dirt from baseboards, cracks, corners, floor registers and air ducts to wipe out bug nesting grounds. Treat these areas with an insecticide.

Empty cabinets and drawers, then clean the interiors with disinfectant and apply a surface insecticide. After allowing time to dry, cover with paper and replace contents. Remove dishes from your cupboards and give a similar treatment.

Cover foods tightly, especially cereals, pet foods and other grain items. Check for bugs before storing food. Never leave food crumbs, dirty dishes, etc. lying on counter tops after a family meal. This means rinsing before putting in the dishwasher, or running the dishwasher immediately. When bringing baskets, bags or boxes into the house, inspect them for roaches that may be hiding in them.

Avoid using insecticides on open surfaces where you are more likely to contaminate your food or dishes than to kill roaches. Regular use of long-acting or residual insecticides behind dishwashers, baseboards and under refrigerators continues to kill new roaches as they emerge from their eggs. Most insecticides will last for about 60 days.

For long-term prevention, use a product such as Roach Prufe (a boric acid powder formula), which can be applied as above. Also consider spaces under cabinets (drawer spaces--remove drawers and apply underneath), in closets, under carpeting, any dark, dank spaces where these critters hide. Cockroaches collect this powder on their legs and return to the nest where they ingest it and die. Don't overlook treatment of areas where papers are stacked or books are kept. These are natural feeding grounds for roaches. Another commercial product effective in controlling roaches is Combat, a bait tray that contains a substance the roaches also carry back to the nest.

Unusual or severe infestations should be referred to a licensed pest control operator who is equipped to handle difficult pest problems. If you live in a condominium or apartment, the problem needs to be treated for the entire building, as roaches will travel from one location to the other on water and drain pipes, etc. If an entire building is infested, hire a professional and then work with your neighbors on the above prevention steps to avoid a repeat of the infestation.

Look for Roach Prufe at your local hardware store or home center, or contact the manufacturer, Copper Brite Inc., 1482 East Valley Rd., Santa Barbara, Calif. 93108. Combat is readily available at hardware and home stores or your local supermarket.

Send e-mail to copleysd@copleynews.com or write to Here's How, Copley News Service, P.O. Box 120190, San Diego, Calif. 92112-0190. Only questions of general interest can be answered in the column.