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How to keep insects where they belong—outside

When it comes to home invaders of the insect variety, Donald McCarthy knows the usual suspects in Atlantic Canada: earwigs and sowbugs—especially in Newfoundland; fire ants in Halifax and New Glasgow, NS; centipedes, silverfish and carpenter ants wherever it's damp; ticks where there's long grass, particularly in Nova Scotia; cluster flies near farms or subdivisions with lush grasses; bedbugs—largely in communal living environments all over Atlantic Canada; and spiders and ants everywhere.

“Our head office receives thousands of calls a year for help dealing with all types of insects,” says McCarthy, president of an Atlantic Canadian pest management company, “but there’s no question that ants are the number one pest, from New Brunswick to Newfoundland. One day last summer, we had 600 calls for ants alone.”

Entomologists attribute the rising incidence of ants and other insect pests to global warming and mild winters, but whatever the reason, more and more homeowners are turning to companies like McCarthy’s for help.

“It’s important to know that we don’t just go in spraying,” says McCarthy. “We identify the pest, investigate why it’s there, establish the most effective and eco-friendly way to eliminate it, and then take steps to prevent it from returning.”

It’s an approach described as Integrated Pest Management (IPM), a common-sense strategy that makes use of three basic steps: inspection, identification and treatment, and puts the emphasis on prevention.

Insects, like the one shown above, can become a big problem once they've moved indoors. The best defence: fill cracks before they get in.

IPM relies on techniques and products that have the lowest risk to health and that place the lightest load on the planet. IPM does include the use of pesticides, but only after other methods have been entirely exhausted.


Like most common criminals, household pests are guided by motive, means and opportunity, so once you’ve determined your home is vulnerable—and you have a good idea what kind of insect is trying to get in—it’s time to eliminate the opportunity for those invaders to enter.

Basically, this boils down to standard home maintenance: sealing exterior cracks, weather-stripping windows and doors, repairing damaged screens and plugging any holes in the foundation.

The next step is to remove the food supply that motivates insects to enter the home in the first place. After ensuring foods have been stored in airtight containers, this step consists of general housekeeping measures like brushing crumbs from the breadboard and around the toaster; cleaning spills promptly; rinsing bottles and cans before placing them in the recycling bin; washing pet bedding and bowls frequently; and sweeping and vacuuming regularly—even behind appliances.

Some insects, like silverfish, love a good book—as long as the pages are a bit soggy. Simple steps to eliminate the damp conditions that attract those slinky devils include repairing leaky pipes and dripping faucets, directing downspouts away from the house, and not overwatering plants on the home’s perimeter.

To further remove moisture from the air and improve ventilation, it’s a good idea to run the bathroom fan when you’re bathing or showering, and to run the cooktop fan when cooking. It’s also wise to use a dehumidifier in the basement.


Once the home is secure and issues with dampness resolved, it’s time to deal with any pests that continue to pose a problem. Although it’s tempting to reach for poisons, foggers and sprays—especially if insects have plagued the house for a period of time—the Sierra Club of Canada encourages homeowners to forego using pesticides whenever possible, and instead to consider making eco-friendly insect sprays from non-toxic household ingredients such as dish soap, cayenne pepper, lemon eucalyptus oil and peppermint scent (see “Spray Goodbye,” page 66).

But while sprays made from soap and water are relatively harmless, Health Canada recommends using care when preparing and storing homemade pesticides, because they may pose health and environmental safety risks for both humans and pets.

The health risks include inhaling harmful fumes, experiencing irritation of the eyes or skin, ingesting contaminants or harmful substances, and potentially contaminating the cookware and utensils you normally use to prepare your food.

“People should be careful when making their own concoctions,” agrees McCarthy. “I’ve seen directions for making some scary sounding solutions. Just remember that arsenic is a ‘naturally occurring’ product. Some of these mixtures could be dangerous.”

Consult the experts

Unfortunately, there are times when it takes more than non-toxic substances to eliminate a pest problem. The solution, for many, is a domestic class insecticide, the designation used by Health Canada’s Pest Management Regulatory Agency (PMRA) for products intended for use by the public in or around the home. The PMRA regulates and tests all of the insecticides you see on the retail shelves in Canada, and says that, when they are used according to the label’s directions, approved products have low toxicity and pose a minimum risk to people and the environment.

“With these products, the label is the law,” says McCarthy. “And unfortunately, sometimes they don’t come with good instructions on how to apply them.” He advises care in the use of these insecticides.

Obviously the best risk is no risk at all, so researchers are experimenting with innovative ways to control insect pests. Some scientists have had success controlling bedbugs and cockroaches by using benign pheromones (chemical substances produced by the insects themselves) to disrupt insects’ reproduction cycles and to lure them into traps.

Clearly, it takes time and effort to work the bugs out.

10 tips for non-toxic pest control

  1. Ants don’t like getting their feet sticky; deter them by applying double-sided tape to thresholds and windowsills.
  2. Pour boiling water on ant nests. It may not exterminate the ants, but it will sometimes cause them to relocate.
  3. Catch and release an insect by trapping it against a window or wall in a clear drinking glass. Slide a piece of paper into place over the mouth of the glass, then release the insect outdoors.
  4. Discourage insects from living nearby by keeping areas close to the house free of firewood and decaying organic matter.
  5. Shake laundry to dislodge hitchhikers like earwigs before bringing it in from the clothesline.
  6. Store books in dry areas to discourage insects such as silverfish from lodging in the spines.
  7. Put a vegetation- and mulch-free border around the foundation of your house and trim the plantings around your home’s perimeter.
  8. Make your own bug-deterring sprays for doors, thresholds, and window casings (see “Spray Goodbye,” page 66).
  9. Deter clothes moths with cedar chips and lavender.
  10. Clean kitchen drains with baking soda and vinegar to discourage fruit flies.

Spray goodbye

Nova Scotia’s Ecology Action Centre recommends these recipes for creating bug-deterrent sprays:

  1. Garlic spray can keep insects from eating household plants and may prevent ants from entering your home; simply crush 10 to 15 cloves of garlic, mix with 2 cups (500 mL) of water, steep overnight, then strain and spray.
  2. A mixture of half vinegar (white or apple cider) and half water can be sprayed on any cracks or crevices where insects enter.
  3. A few drops of peppermint oil in 2 cups (500 mL) of water will also keep insects at bay—but note that this spray could be harmful to cats.

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