3 Ways To Block Home-Invading InsectsTake action to minimize – or even prevent – the annual fall insect migration into your home. Three types of barriers provide an effective measure of protection against insects: physical, chemical and cultural. Use one method or, better yet, adapt techniques from all three types of barriers to create a strong defense against invading insects.

Physical Barriers

One type of physical barrier blocks openings into your home. Caulk around windows (especially basement windows), seal cracks around crawl space or attic vents, and replace worn weatherstripping around doors. These actions not only keep bugs out, but also reduce energy bills. Check concrete walls around basement windows; repair any cracks. Double-check screens to ensure a tight fit.

Make sure doors aren’t left standing open; it only takes a second for an insect to scamper or fly inside. If cluster flies – slow-moving flies that cluster at windows and bump into you as they fly – are gathering, grab a fly swatter or hang fly strips near doors or sunny windows.

Chemical Barriers

Keep insects from gaining access to your home by applying an insecticide at least 1 to 2 feet from the ground up, along the foundation, and also 1 to 2 feet from the foundation wall outward, along the ground. You can create a larger barrier, if you like, of 4 to 5 feet. A granular product may or may not provide longer protection than a liquid spray.

Cultural Barriers

Cultural barriers provide another line of defense against insect invaders, eliminating conditions that make your home – and the area around it – desirable habitat.

  • Move plants away from your foundation. Trim shrubs and trees so branches don’t touch or overhang your home, which can provide a footbridge for insects to cross over a perimeter insecticide treatment.
  • Don’t store firewood indoors. Outside, keep it away from the walls of your home and elevated off the ground. Many insects overwinter in wood. When it sits indoors and warms up, insects think it’s spring and come crawling out.
  • Use downspouts to direct water away from your foundation. Most insects cannot regulate body moisture and seek damp conditions. Keep your home’s foundation dry.
  • Clean up stones, leaf litter, bricks, logs, plant debris and other items that provide hiding places for insects. This is vital to control ground beetles, which seek these hiding places and also feed on insects that shelter in these same hiding places.
  • Remove host plants for specific insects that plague your home. For example, if elm leaf beetles overtake your home each year, consider removing elm trees from your landscape.
  • Keep window wells free of leaf litter and other plant debris that provide hiding places for spiders or roaches.
  • Reduce mulch thickness to 2 to 3 inches maximum and keep it 6 to 8 inches away from the foundation. This helps eliminate millipedes.
  • Store pet food tightly sealed containers to avoid attracting ants and roaches. Clean up any spilled food or unused water before dark.
  • Turn off outside lights at night to avoid attracting insects, especially when crickets are actively gathering and invading.

For more tips on preventing insects from entering your home, see Home Pest Prevention Basics.