Controlling insects in your home comes down to three things: cutting off what attracts them, sealing the gaps they use to get inside, and treating strategically when prevention alone isn’t enough. Most household insect problems can be handled without a professional, but knowing which pests you’re dealing with changes the approach entirely.
Identify the Pest First
Before you buy any product or set any trap, figure out what you’re actually dealing with. Different insects need different strategies, and misidentifying a pest wastes time and money. A few of the most common indoor insects and where you’ll typically spot them:
- Drain flies: Tiny (about 2mm), gray, fuzzy, moth-like insects found near bathroom sinks and drains. They breed in the organic buildup inside pipes.
- Indian meal moths: About 5/8 inch long with reddish-copper wings, almost always found in the kitchen or pantry. They infest stored grains, flour, and cereal.
- Carpet and drugstore beetles: A quarter inch or smaller, oval-shaped, brown or black. They can show up in any room and feed on a surprisingly wide range of materials.
- Clothes moths: Small buff-colored moths with a 3/8 to 1/2 inch wingspan, usually hiding in closets or bedrooms where they feed on natural fibers.
- Fleas: Tiny (1/16 to 1/8 inch), brownish-black, wingless, and flattened side to side. They jump rather than fly and bite humans and pets.
- Bark beetles: Small cylindrical beetles that emerge from firewood, often noticed near windows or woodpiles in winter. Look for small round holes in the bark of your firewood logs.
One identification that should get your immediate attention: termite swarmers. These are dark brown, about 1/4 inch long, with four wings of equal length. They often emerge indoors from hidden colonies. If you see them, that signals an active infestation in or near the structure of your home.
Your local county extension office can help identify insects for free. Many accept photo submissions online.
Seal the Gaps They Use to Get In
Exclusion, the practice of physically blocking entry points, is the single most effective long-term insect control measure. Insects don’t need much space. A gap of just 1/16 inch under a door or around a window frame is wide enough for ants, spiders, and most small insects to walk right through.
Start with exterior doors. Lie on the floor and look for daylight under and around each one. Install door sweeps or thresholds at the base, and run a bead of caulk along the bottom outside edge and sides of the threshold. Garage doors need a rubber bottom seal (vinyl cracks in cold weather and stops sealing properly). For sliding glass doors, line the bottom track with 1/2 to 3/4 inch foam weatherstripping.
Next, check where utilities enter the house. Pipes, wires, outdoor faucets, gas meters, dryer vents, and cable lines all create openings in the foundation or siding. These are some of the most common entry points for ants, spiders, and wasps. Plug them with caulk, cement, expanding foam, steel wool, or copper mesh depending on the size of the gap. For caulking around windows, doors, and fascia boards, a good quality silicone or acrylic latex caulk works well. Latex types clean up with water and can be painted over.
Repair any torn or damaged window and door screens. If you have attic, roof, or crawl space vents, cover them with 1/4 inch wire mesh to block larger pests from nesting inside.
Remove What Attracts Them
Insects come inside looking for food, water, and shelter. Removing even one of those makes your home far less hospitable. Store all food (including pet food) in sealed containers. Fit your garbage can with a tight lid. Fix leaking faucets and pipes, since even a slow drip provides enough water for many insects to thrive.
Vacuum carpets and rugs regularly. This picks up crumbs that attract pests, but it also removes insect eggs and larvae you can’t see with the naked eye. For pantry pests like Indian meal moths, discard any infested items and thoroughly clean the storage area. That alone often eliminates the problem.
Keep indoor humidity low. Excess moisture encourages mold growth, which feeds certain insects and attracts others. Clutter doesn’t necessarily attract insects, but it gives them places to hide and breed undisturbed. Reducing clutter, especially in basements, closets, and storage areas, makes it easier to spot problems early.
One commonly overlooked source of new infestations: items you bring into the house. Used furniture, rugs, and secondhand clothing can carry hitchhiking insects. Inspect them before bringing them inside. Running clothing and bedding through a dryer on high heat kills eggs, larvae, and adult insects.
When and How to Use Insecticides
If prevention and exclusion aren’t enough, targeted insecticide use is the next step. The key word is targeted. Spraying broadly around your home is less effective and creates unnecessary chemical exposure.
Two of the most useful low-toxicity options for indoor use are diatomaceous earth and boric acid, both sold as dusts. Diatomaceous earth works mechanically rather than chemically. It absorbs oils and fats from an insect’s outer shell while its sharp microscopic edges abrade the surface, causing the insect to dry out and die. It doesn’t need to be eaten to work. It stays effective as long as it remains dry and undisturbed, making it ideal for cracks, crevices, behind appliances, and along baseboards. It’s registered for use against cockroaches, bed bugs, fleas, ticks, crickets, spiders, and many other pests. Boric acid works similarly as a dust and is also a common active ingredient in insect baits.
For faster knockdown, spray products typically contain pyrethrins (derived from chrysanthemum flowers) or synthetic versions of the same compounds. Pyrethrins kill on contact but break down quickly and leave little residue. Longer-lasting residual sprays use synthetic compounds that persist on surfaces for weeks, providing ongoing protection along baseboards, window frames, and other entry points.
Baits are particularly effective for ants and cockroaches because foraging insects carry the bait back to the colony, which can eliminate the source rather than just the individuals you see.
Safety Around Kids and Pets
Only use products specifically labeled for indoor use. The label isn’t just a suggestion; it tells you the concentration and formulation are appropriate for enclosed spaces where people breathe the air and touch treated surfaces.
If you need to mix or dilute a pesticide, do it outside, even if the treatment itself goes indoors. When applying pesticides to your yard or exterior, close all windows and doors first. After outdoor lawn treatments, keep people and pets off the treated area until it dries completely and any granules are no longer visible. Remove your shoes at the door afterward and check pant cuffs and laces for granules that may have gotten stuck.
Diatomaceous earth is a good option for homes with children and pets because it’s not a chemical poison. That said, the fine dust can irritate lungs if inhaled during application, so apply it in thin layers in areas that won’t be disturbed by foot traffic or play.
When to Call a Professional
Most indoor insect problems are nuisances you can handle yourself through exclusion, sanitation, and targeted treatment. Pantry moths go away once you discard infested food and clean the shelves. Occasional invaders like bark beetles or stray ants can be vacuumed up or blocked out. But certain pests genuinely require professional help.
Termites, carpenter ants, and wood-boring beetles are the clearest cases. These insects damage the structure of your home, and treatment requires specialized equipment and knowledge of building construction. Bed bugs are another strong candidate for professional treatment. Their ability to hide in tiny crevices and their resistance to many consumer products makes DIY elimination difficult and often incomplete. Stinging insects like hornets or fire ants that have established nests in or near the home also warrant a professional, both for safety and effectiveness.
When choosing a pest control service, look for licensed operators who can explain exactly what they plan to do and what chemicals they’ll use. A reputable company will inspect before proposing treatment and should be willing to answer questions about safety precautions for your household.