Getting rid of bugs in your house comes down to three things: cutting off what attracts them, sealing the ways they get in, and treating the ones already inside. Most infestations can be handled without an exterminator if you combine these steps rather than relying on any single fix. The approach works whether you’re dealing with ants, cockroaches, spiders, silverfish, or other common household pests.
Figure Out What You’re Dealing With
Before you start spraying anything, identify the pest. Different bugs need different strategies, and misidentifying them wastes time and money. Look for droppings, damage patterns, and where you’re spotting activity. Small cockroach droppings (from German cockroaches, the most common indoor species) look like black ground pepper or coffee grounds. Larger species like American cockroaches leave pellets shaped like grains of rice with ridged edges, which distinguishes them from mouse droppings, which have smooth edges. Cockroach waste tends to appear scattered wherever they travel: inside cabinets, under appliances, along baseboards, and in corners.
Ants leave visible trails and often cluster near food or water sources. Bed bugs leave tiny rust-colored spots on sheets and mattress seams. Silverfish chew irregular holes in paper, wallpaper, and fabrics. Once you know the pest, you can target your efforts instead of taking a scattershot approach.
Seal Every Entry Point
This is the step most people skip, and it’s the most important one for long-term results. Insects and spiders can squeeze through gaps as small as 1/16 of an inch. Mice need only a quarter-inch gap (about the diameter of a pencil), and rats can fit through half-inch openings. Your house likely has dozens of these entry points right now.
Start with exterior doors. Lie on the floor and look for light filtering underneath. Install door sweeps or thresholds at the base of every exterior door, and pay special attention to the bottom corners, which are the most common entry points for both insects and rodents. Apply caulk along the bottom outside edge and sides of door thresholds to block ants and other small insects. For garage doors, use a rubber bottom seal (vinyl performs poorly in cold weather). Sliding glass doors can be sealed by lining the bottom track with half- to three-quarter-inch foam weatherstripping.
Next, seal utility openings where pipes and wires enter the foundation and siding: outdoor faucets, electrical receptacles, gas meters, dryer vents, and cable lines. These can be plugged with silicone caulk, expandable foam, steel wool, or copper mesh. For cracks around windows, doors, and fascia boards, use a quality silicone or acrylic latex caulk. Latex types clean up easily with water and are paintable. Clean cracks and remove any peeling caulk before applying new sealant.
Repair tears in window and door screens to keep out flies, gnats, and mosquitoes. Note that some insects, like leafhoppers, are small enough to fit through standard mesh, so keeping windows closed during peak activity is sometimes the only option. If you have attic, roof, or crawl space vents, cover them with quarter-inch wire mesh hardware cloth to block larger pests and wildlife.
Eliminate Food, Water, and Shelter
Bugs are in your house because it offers what they need to survive. Remove those resources and most populations shrink dramatically on their own. Store all pantry food in airtight containers, including pet food. Wipe down counters and sweep floors daily, especially in the kitchen. Take garbage out regularly and use bins with tight-fitting lids. Even small crumbs under a toaster or grease splatter behind a stove can sustain a colony of ants or cockroaches for weeks.
Water is just as important as food. Fix leaky faucets, pipes, and any condensation issues under sinks. Empty standing water from plant saucers, pet bowls left overnight, and dehumidifier trays. Many moisture-loving pests like silverfish, springtails, and dust mites thrive when indoor humidity rises above 60 to 70 percent. Keep your home’s relative humidity between 30 and 50 percent using exhaust fans, dehumidifiers, or air conditioning. This range also discourages mold growth, which feeds certain insects.
Declutter storage areas like basements, attics, and closets. Cardboard boxes are a food source for silverfish and a hiding place for cockroaches and spiders. Switch to plastic bins with lids. Move firewood away from the house and trim vegetation that touches exterior walls, since branches and shrubs act as bridges for insects.
Low-Toxicity Treatments That Work
For bugs already inside, two powder-based treatments are effective and widely available: diatomaceous earth and boric acid. They work differently and have different safety profiles.
Diatomaceous Earth
Food-grade diatomaceous earth kills insects physically, not chemically. Its microscopic particles are sharp enough to puncture the waxy coating on an insect’s exoskeleton, causing the bug to lose fluids and die of dehydration. When insects try to groom the powder off their legs and joints, they ingest it, which absorbs moisture internally and accelerates the process. It works on cockroaches, ants, bed bugs, fleas, spiders, silverfish, and ticks.
Apply a thin, barely visible layer in cracks, along baseboards, behind appliances, and inside wall voids. A heavy pile is less effective because bugs will walk around it. The powder stays effective indefinitely as long as it remains dry and undisturbed. Use only food-grade diatomaceous earth, which is low in crystalline silica and safe around people and pets once settled. Wear a mask during application to avoid inhaling the dust. If you do inhale some, food-grade particles are rapidly cleared from lung tissue.
Boric Acid
Boric acid is a more potent insecticide, registered with the EPA as a pesticide product. It’s particularly effective against cockroaches and ants when applied as a thin dust in hidden areas: behind outlet covers, inside cabinet voids, and under appliances. Insects walk through it, ingest it during grooming, and die within days.
However, boric acid requires more caution. It can burn or irritate skin, eyes, and mucous membranes. Repeated exposure or ingestion of powdered boric acid products can cause poisoning in pets and humans. Keep it strictly in areas children and animals cannot reach, and never apply it to food preparation surfaces.
When to Use Chemical Sprays
If physical exclusion and dust treatments aren’t enough, chemical insecticides can help, but they should be your last step, not your first. Only use products specifically formulated for indoor use. Read the label directions completely before application, including the required ventilation time. Mix and dilute pesticides outdoors, even when you plan to spray inside.
Good ventilation reduces the concentration of pesticides in indoor air, so open windows and run fans during and after treatment. Many people don’t realize that disinfectants and antimicrobial cleaners are also classified as pesticides and carry similar ventilation requirements.
Targeted baits (gel baits for cockroaches, bait stations for ants) are generally safer and more effective than broadcast sprays because they attract insects to a specific toxicant rather than coating surfaces throughout your living space. Spray treatments can actually scatter certain pests, like cockroaches, into new areas of your home, making the problem worse.
What About Essential Oils?
Peppermint oil, cinnamon, and other essential oils are frequently recommended as natural bug repellents. There is some evidence behind this. Mint oil repels fire ant workers, and extracts from camphor and cinnamon plants show toxicity to certain ant species. Essential oils can inhibit feeding, prevent egg hatching, and kill insects at various life stages.
The catch is their high volatility. Essential oils evaporate quickly, which means any repellent effect fades fast and requires repeated application. Research on their effectiveness is also inconsistent. Studies vary widely in methods and dosing, making it difficult to say how well any particular oil works at the concentrations available in consumer products. They can be a useful supplement, particularly for deterring ants from a specific entry point, but they won’t resolve an established infestation on their own. With repeated use, insects can also develop resistance.
A Practical Order of Operations
The most effective approach follows a logical sequence rather than jumping straight to pesticides:
- Identify the pest so you can target your strategy.
- Clean aggressively to remove food and water sources.
- Seal entry points with caulk, weatherstripping, mesh, and door sweeps.
- Reduce humidity to 30 to 50 percent relative humidity.
- Apply dust treatments like diatomaceous earth in cracks, voids, and hidden pathways.
- Use targeted baits for persistent populations of cockroaches or ants.
- Resort to sprays only when other methods haven’t controlled the problem, and always with proper ventilation.
This layered approach is the basis of integrated pest management, the framework recommended by the USDA for minimizing health and environmental risks while actually solving the problem. Each step reduces the pest population and makes the next step more effective. Skipping straight to chemical sprays without sealing gaps and removing attractants is why so many people find bugs coming back within weeks.