Guiltless Pest Control

The year-round war against rodents and insects always heats up as the seasons change, so it's time to start planning your battle strategy.

Many of us, however, have grown uncomfortable with traditional methods of dealing with pests. Old-line products, those that have not already been pulled off of the shelves by the Environmental Protection Agency, often rely on toxins that may be carcinogenic, detrimental to the endocrine (hormone) system or irritating to skin, eyes or respiratory systems.

Research has linked pesticides to medical problems ranging from asthma to brain cancer. And these chemicals have an uncanny way of showing up in the environment, including our food supply, far from where they were applied.

Even when pesticides are only suspected of being a health problem, you may wonder: Why take a chance, especially if low-risk, "green" alternatives are available.

New and better ways
Nontoxic approaches to pest control kill or deter pests without using poisons or hazardous chemicals. One new agent works by interfering with insects' growth hormone and interrupting molting patterns. (Insects with exoskeletons must molt to grow or they die.)

Often effective for subterranean termites, this method uses baiting stations that consist of a cellulose food source and a cartridge containing termite-killing agents. Stations are placed every 8 to 10 ft. around the house. Eventually, a termite bumps into one, eats its way into the cartridge and leaves a pheromone trail for others to follow. (In some systems, the cartridge is added after termite activity has been observed at the station.)

"The big drawback," says John Chapman, manager of technical services for The Terminix International Co., "is you have to get termites to take the bait. Also, the process is labor intensive." An alternative solution uses a new control agent, fipronil, which blocks nerve transmission in insects but not mammals and is effective, long-lasting and low in toxicity. "It is also low in solubility, so it does move in the soil," Chapman says.

Not-so-new methods
Not all environmentally responsible pesticides are new. Diatomaceous earth (DE) has been used for decades and modern processing has improved its effectiveness. You may remember the fine white powder from your chemistry set. Put it under a microscope and you'll find tiny fossils of diatoms, which are algae with a skeleton made from silica. The sharp edges of these fossils kill many types of insects, cockroaches and beetles. The fossils adhere to and pierce the insect's waxy coating, causing the critter to dehydrate and die.

Herman Tripp of White Mountain Natural Products says, "We've found it to be an effective barrier when sprinkled between studs of exterior walls." DE can also be sprinkled on carpets to control fleas, mites and ticks.

The nice thing about DE is pests don't become resistant to it, as they do with many toxic pesticides, although insects such as ants and termites are smart enough to avoid the powder. Tripp advises homeowners to steer clear of finely ground DE, the kind used in paint pigments, which is so lightweight that it disperses into the air.

Another lower-toxicity pesticide, boric acid, is a white powder that is used in dozens of pest-control products. Safe for use around humans and pets, as long as it is not swallowed or inhaled or does not come in contact with the eyes, boric acid affects insects' nervous systems and acts as a desiccant, drying out the body. It is effective for a wide range of insects, including palmetto bugs, cockroaches, carpenter ants and termites. Exterminators often use a mixture of equal portions of boric acid and peanut butter or honey to attract ants, which then carry the pesticide back to the nest. However, it's essential that the sweet bait be placed where children and pets won't find it.

Killer chrysanthemums
Other nontoxic products with ingredients that don't harm humans but that kill bugs on contact or soon thereafter include:
Pyrethrin - Derived from chrysanthemums, this agent dispatches aphids, cockroaches and beetles. (Keep in mind, however, that even natural products can act as asthma triggers.)
Mint oil and citrus-based sprays and gels - These products kill ants, centipedes, crickets, spiders and many other insects quickly. Their natural ingredients make them safe around children and pets. (And they smell a lot better than chemical sprays.)
Glue traps - These devices are nontoxic and effective for beetles, flies and moths. When setting tent- or cigarette-shape cardboard traps, insert the supplied attractant and place it in an infested cabinet or, to control flies, next to a window.

Tried-and-true traps
Though animal-rights activists might take issue with their use, rodent traps that kill quickly are environmentally friendly because they don't use poisons. Standard spring-action traps, baited with peanut butter or cheese for mice and peanut butter or bacon for rats, are highly effective. To lure rodents into a false sense of security, place the traps in areas where activity is suspected, but don't set them for the first few days. This allows rodents to get used to the traps and stop seeing them as a threat.

When you set the traps, use small amounts of bait that the animal must struggle to reach. Place traps along walls, where rodents typically travel, with the baited end against the wall. Check traps daily, and wear gloves when disposing of trapped animals.


Place mousetraps or bait stations where floors and walls meet and in dark corners. Proper positioning increases the likelihood of killing rather than just injuring a mouse.

Although sticky paper traps for rodents might seem more humane than lethal versions, they actually cause hapless pests (as well as sympathetic family members) unnecessary agony. These types of traps can also accidentally get stuck to pets and children.

Keep in mind that killing existing rodents and insects may not solve an infestation problem. Many types of ants, for example, repopulate unless you treat the parent nest, which may be inside the home or outside. Careful observation can help locate the nest.

Repulsive approaches
Softhearted homeowners may prefer to repel rather than poison unwanted visitors. Rat and mouse repellents target the animals' highly developed sense of smell or hearing. Sulfur compounds, for example, are effective in reducing rat and mouse activity in buildings and garbage-collection areas. Ultrasounds-wave emitters, found in hardware stores, produce frequencies (typically over 30 kilohertz) that hurt rodents' ears, driving them away. Humans and pets other than rodents can't hear these frequencies and remain unaffected.

Whether ultrasound consistently works is a subject of debate, and most ultrasound systems have drawbacks. For example, results are not instantaneous; it can take a week to drive rodents out. And because sound waves do not penetrate walls, you need an emitter for every room where you suspect infestation.

Catch and release
For the true Buddhist at heart, catch-and-release may be the most environmentally friendly option. If you're brave, catching a spider in a napkin and releasing it outdoors is not much more bothersome than stomping it and cleaning up a smudge. Many humane live traps, typically baited with peanut butter, are available to catch rats and mice. Most catch one rodent at a time, but some will trap several. Wind-up traps can capture entire families of mice in one setting. When a mouse steps on the trap's threshold, it is swept into an escape-proof box.


The One-Way-Door Excluder by Tomahawk is a safe way to capture critters that have already invaded your home. The trap is attached to the exterior of your house over the entry hole and allows the animal to exit in search of food but blocks it from reentering.

Catch-and-release is not for the lazy, it usually entails driving to a remote release point. And once you get there, it can be difficult to persuade frightened captives to leave the trap.

Proactive strategies
The most effective pest control comes from taking proactive rather than reactive measures, so develop control strategies before pests invade. "It's a lot easier to eliminate or repel one insect or rodent than to deal with entire colonies or nests," says George Allen, CEO of Inject Solutions.

To help minimize pest invasion, the company developed Thermal Wall Injection System & Treatment (TWIST), a pest-control system involving injector plugs that are placed through interior and exterior walls (drywall, block walls, siding, etc.) or through the bases of floor cabinets. With a squeeze-bottle or aerosol can, homeowners periodically apply a control agent that is dispersed through the plug.


Install TWIST plugs about 10 in. from the floor to steer clear of electrical lines. Optimal locations include moist areas near air conditioning ducts and water pipes and north walls of homes. Most houses need about 12 plugs, which cost about $8 each.

"The beauty of this system is it delivers the agent to where pests live, inside walls and under cabinets. It's a waste to dust baseboards with pesticides that will only get wiped up the next time the floor gets mopped," says Allen. The system also keeps pesticides away from people, pets and living spaces.

Whichever pest-control strategy you choose, take steps to make your home less inviting to pests. Seal all openings in exterior walls with copper mesh and caulk. Remove or store all food sources, including bags of dog food and birdseed, in pest-proof containers. Use locking garbage-can lids to keep pests out of the trash, and cover any foodstuffs in compost bins.

Also remove piles of wood, stone or rubble near the house that could serve as havens for rodents and insects. Keep flowers and shrubs, which can harbor insects, at least 3 or 4 ft. from the house. To prevent rodents from using trees to access the roof, keep branches at least 5 ft. away. Instead of bark or other organic mulch, use pea gravel, which provides a more hostile environment for insects. Most important, solve moisture problems. Pests need water, and it's often supplied by faulty gutter systems, sweating pipes and leaking spigots.

Remember, the "greenest" approach to solving pest problems is prevention. Preempting a pest attack will help you save money as well as preserve the environment.