Have you ever had one of those “EEEEK!” moments when you watched an army of ants march across your kitchen counter? Seen centipedes scurry along your basement floor? Spied spiders lurking in the corners of your entryway? If so, you know how quickly your home can turn into an AirBNB for unwanted pests.
The good news? Most insect infestations don’t require pesticides or complicated fixes. All it takes is sealing entry points, like gaps under doors, worn weatherstripping, and small cracks in the foundation. Plugging these spots is one of the most effective ways to put an end to unwelcome visitors — and most of these projects can be knocked out in a weekend with basic tools and inexpensive materials.
Why sealing matters more than spraying—and where to start
When they see bugs, many homeowners’ first instinct is to reach for bug sprays or traps. But those solutions only address the symptoms. Bugs are entering your home because they’ve found a way in. Even the tiniest gaps — we’re talking a gap the thickness of a credit card — are big enough for ants, spiders, or cockroaches to get inside. To make your home less inviting, you need to seal the gaps that are letting them in.
Start with Doors
Entry doors are one of the most common entry points for insects. The space around a door may look tight, but there are usually small gaps along the sides and top where the door meets the frame. Over time, the weatherstripping in these areas wears down, flattens, or pulls away. Replacing or upgrading weatherstripping is one of the simplest and most effective sealing projects you can do. (If you’re not sure what type of weatherstripping is right for your project, read this blog post.)
To install, clean the door frame so the adhesive can stick properly, then measure and cut the weatherstripping to fit each side and press it firmly into place, making sure there are no gaps. Watch this video for step-by-step directions:
Add a door sweep
While weatherstripping seals the sides and tops, the gap under a door is often the largest opening where insects, spiders, and even small rodents can get in. A door sweep attaches to the bottom of the door and creates a flexible seal against the threshold. Some are made of rubber flaps, while others use bristles that bend as the door moves. Frost King even makes a door sweep that slides onto the bottom of the door, no installation required. When properly installed, a door sweep can make an immediate difference: You may notice fewer crawling insects overnight.
Seal foundation cracks
The foundation of your home is another major entry point. Small cracks may seem harmless, but they can act like an on ramp into your home for ants, spiders, and other insects. Even worse, moisture can also collect in these gaps, which attracts even more pests. The good news is that most small foundation cracks are easy to seal with basic materials like caulk and caulk saver. Look for gaps near basement windows, utility lines, and where the foundation meets siding. Start by cleaning out debris from the crack with a stiff brush or compressed air.
• To fill narrow cracks, use a flexible exterior-grade caulk designed for concrete or Mortite Fingertip Caulking Cord—just pull off what you need and push it into the cracks.
• Fill deeper cracks with caulk saver before applying caulk over the top.
Watch this video to learn more:
Don’t forget utility openings and other small gaps
While doors and foundations are the biggest offenders, insects will use any opening they can find, including tiny gaps around utility line entry points, air conditioning lines, and dryer vents and exhaust openings. These areas can be easily sealed with steel wool, expanding foam tape, or caulk.
The seasonal advantage of sealing
When it comes to stopping bugs, timing matters. The best time to do sealing projects is right now, when insects are actively searching for food and nesting areas. And remember that sealing isn’t a one-and-done project. Weather, temperature swings, and time will eventually reopen gaps. A quick seasonal check—especially around doors and foundation lines—helps avoid a full-on insect infestation.
