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How to keep insects out of your house, according to an entomologist and other experts

Ants are common household pests. (Timon Cornelissen / Pexels) Ants are common household pests. (Timon Cornelissen / Pexels)

This year's mild winter allowed numerous insect populations to survive and thrive through the season, an entomologist says.

Now that spring is here, and temperatures have warmed up even more, you may be anxious at the thought of bugs invading your home, or you may already be battling the pests.

If you prefer not to use professional pest control services, here are expert tips on how to keep insects away.

You might be tempted to spray the bugs you find indoors, but Alice Sinia, entomologist with pest control company Orkin Canada, suggests people consider squashing that idea.

"The best advice I would give is, first of all, do not try to control them or spray them," Sinia said in a Zoom interview with "That is always the worst thing you can do for these overwintering insects. The best thing is just to let them go back outside."

She says that's because you may create another problem.

"And the reason for that is when you spray them in their overwintering sites, especially when they're inside, let's say they're in the wall or in the attic, they end up dying there," Sinia explained.

"And when that happens, then it becomes a source of food for other insects – for example, warehouse beetles or carpet beetles – because these insects actually feed on other dead insects."

Use a broom or vacuum and dispose of them outside or in a garbage receptacle, Sinia suggests.

There's an exception if you're dealing with stink bugs.

"Stink bugs actually produce a very strong substance, which gives them that smelly, stinky smell," she said. "So vacuuming for stink bugs is usually not the best way to go."

Homeowners can also look for potential entry points for insects and seal them up. Thoroughly inspect and seal cracks, crevices and other openings such as around utility lines, in vents, window screens, door seals and eaves.

"So this not only keeps out these insects, but it also keeps out rodents, especially like mice because mice can get through any opening, which is the size of a dime," Sinia said. "If a homeowner can really seal all these openings, it's going to keep these insects out and it's going to keep also the rodents out."

To avoid insects such as wasps in your property, ensure garbage bins are sealed well and food is covered. You can also buy products such as insect traps to help control or kill bugs.

Light can also attract insects. Sinia recommends using dimmer lights and sensors.

"For example, instead of leaving all the lights on, perhaps use a sensor light which comes on and off so that you don't have these lights all the time blaring on and then it's attracting all these insects ... to the house," she explained.

If you prefer eco-friendly methods to deal with bugs, environmentalists recommend ditching chemicals. Synthetic chemicals can be toxic not only to the pest but also to beneficial insects, pollinators, birds and other wildlife as well as the environment and pose risks to humans, according to the David Suzuki Foundation.

Eco-friendly tips

The national non-profit organization had the following tips on its website:

  • Remove anything that may attract insects. Check for excessive moisture, spills, crumbs or improperly stored food in your home. Leaky pipes or poorly ventilated areas could contribute to the problem.
  • Regularly clean and declutter potential nesting or hiding spots, such as in basements, attics, crawl spaces and storage areas.
  • Pest-repelling plants, such as lavender or marigolds, deter certain bugs such as silverfish, earwigs and firebrats.
  • Ants: Use vinegar to wipe down surfaces to disrupt their scent trails. Spread or spray lemon juice, cinnamon or peppermint oil, or sprinkle diatomaceous earth in areas that may have ants. The strong scent deters ants. After 24 to 48 hours, clean up the diatomaceous earth – a fine powder made from crushed fossilized algae – with a damp rag.
  • Cockroaches: Food, garbage and humidity can attract cockroaches. Spray peppermint, eucalyptus or tea tree oil (diluted in water) around baseboards and other hiding places or entry points. You can also sprinkle bay leaves or catnip sachets.
  • Flies: Ensure garbage and compost bins are sealed shut. Spray a mixture of lavender, peppermint, eucalyptus or lemongrass oil (a few drops diluted in water) in areas flies tend to enter or gather. Or use a mixture with one cup of water and one teaspoon of cayenne pepper, or one tablespoon of peppermint castile soap with one litre of water. Make traps using a jar or bottle filled with apple cider vinegar, dish soap and fruit, which is especially attractive to fruit flies. Get carnivorous plants. Use sticky flypaper strips.
  • Spiders: Spray a diluted mixture from a few drops of peppermint, tea tree and eucalyptus oil on walls, windows and other spider-prone areas. You can also use equal parts vinegar and water as a spray. Remove outdoor lighting from entry points like doors and windows. Yellow or sodium vapour lights are less attractive to night-flying insects, which spiders eat. Top Stories

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