You spotted large black ants trailing across your kitchen counter or heard rustling sounds in your walls at night. These could be carpenter ants, and they’re not just a nuisance. Unlike regular ants that simply forage for food, carpenter ants tunnel through wood to build their nests. Left unchecked, they can seriously damage the structural beams, joists, and framing in your home.
The good news is you can eliminate carpenter ants yourself with the right approach. Success comes down to finding their nests, choosing effective treatments, and fixing the moisture problems that attracted them in the first place. Most infestations respond well to baits, dusts, or targeted sprays when you apply them correctly.
This guide walks you through proven methods to identify carpenter ant activity, locate their colonies, and eliminate them for good. You’ll learn when DIY treatments work, which products to use, and when professional help makes more sense. We’ll also cover prevention strategies to keep these wood destroying pests from coming back.
Understand carpenter ants and key warning signs
Before you can effectively get rid of carpenter ants, you need to confirm you’re dealing with the right pest. Carpenter ants measure 1/4 to 1/2 inch long and appear mostly black or dark reddish brown. They have a distinctive narrow waist, bent antennae, and large mandibles they use to chew through wood. You might confuse them with termites, but termites have straight antennae, equal-sized wings, and thick waists.
What carpenter ants look like
Worker carpenter ants range from small to large within the same colony. The largest workers grow up to 5/8 inch, making them noticeably bigger than common house ants. Winged carpenter ants (swarmers) appear in spring with unequal wing lengths, the front pair longer than the back. These reproductive ants signal a mature colony nearby, often inside your home.
Signs of carpenter ant activity
You’ll spot several clear indicators when carpenter ants invade your property. Frass (wood shavings mixed with ant body parts) accumulates below exit holes in wood. You might hear faint rustling sounds inside walls during quiet hours as ants excavate galleries. Live ants consistently appear indoors, especially near moisture sources like kitchens, bathrooms, or leaky pipes.
Finding 20 or more large black ants inside during winter strongly suggests an indoor nest, since outdoor colonies remain dormant in cold weather.
Step 1. Inspect your home and confirm activity
Start your inspection during late evening or early morning hours when carpenter ants are most active. Turn off indoor lights and use a flashlight to trace ant trails back to their entry points. You need to confirm these are actually carpenter ants and not a different species before choosing how to get rid of carpenter ants effectively.
Check common entry points
Walk around your home’s exterior and look for cracks in the foundation, gaps around windows, and spaces where utility lines enter. Carpenter ants often follow tree branches or shrubs that touch your house, so trim back any vegetation within 3 feet of your structure. Inside, focus on areas with moisture:
- Kitchen and bathroom sinks (check under cabinets)
- Windows with condensation or water damage
- Basement walls and crawl spaces
- Attic vents and roof eaves
- Door frames and window sills
Document what you find
Take photos of ant trails, frass piles, and damage you discover during your inspection. Count how many ants you see and note the time of day they appear most active. This information helps you determine the infestation’s severity and track your progress after treatment.
Record which rooms have the most activity, since nests are typically located within 300 feet of where foraging ants appear.
Mark suspected nest locations with painter’s tape so you can monitor these spots for increased activity over the next few days.
Step 2. Find nests and fix moisture problems
Carpenter ants always nest in moisture damaged wood or areas with consistently high humidity levels. Your inspection should focus on tracking foragers back to their colony and then addressing the underlying water problems that made your home attractive. Without fixing moisture issues, new colonies will simply move in after you eliminate the current infestation.
Locate the main nest
Follow active ant trails during peak hours to narrow down potential nest locations. Tap suspected wood with a screwdriver handle and listen for a hollow sound, which indicates excavated galleries inside. Carpenter ants prefer structural wood near water sources, so check behind dishwashers, under bathtubs, and around leaking pipes first.
Look for frass piles (wood shavings mixed with dead ant parts) below small holes in wood surfaces. These exit holes are usually about 1/8 inch wide and indicate active tunneling nearby. Parent nests outdoors typically sit in dead tree stumps, firewood piles, or rotting fence posts within 300 feet of your house. Satellite nests indoors can hide in wall voids, attics, or crawl spaces where moisture has damaged the wood.
Carpenter ants need moisture to survive, so nests are almost always within 10 feet of a water source or previously water damaged area.
Eliminate moisture sources
Fix all plumbing leaks immediately, even minor drips under sinks or behind toilets. Replace any water damaged wood you find during your inspection, since this material will continue attracting carpenter ants. Improve ventilation in basements and crawl spaces by adding dehumidifiers or increasing air circulation with fans.
Clean your gutters twice yearly and extend downspouts at least 6 feet away from your foundation. Seal cracks in your foundation with hydraulic cement and ensure proper grading slopes water away from your house. These moisture control steps are essential for how to get rid of carpenter ants permanently, since dry conditions make your property unsuitable for colony establishment.
Step 3. Use baits, dusts, and sprays safely
Once you’ve located nests and fixed moisture problems, you’re ready to treat the infestation with proven pest control products. The most effective approach to how to get rid of carpenter ants combines three treatment methods: slow acting baits that workers carry back to the colony, insecticidal dusts for wall voids and hidden spaces, and perimeter sprays to block entry points. Apply treatments in the evening when foraging activity peaks for maximum effectiveness.
Apply baits for colony elimination
Place gel or granular baits within 10 feet of ant trails you observed during your inspection. Carpenter ants prefer protein based baits in spring and sugar based baits in summer, so rotate between formulas if one type doesn’t attract them. Position bait stations every 15 feet along active trails and near suspected nest locations, but never spray insecticides near baits since this repels ants before they can feed.
Workers consume the bait and carry it back to feed nestmates, including the queen and developing larvae. This process takes 7 to 10 days before you notice reduced activity, so resist the urge to spray ants you see during this waiting period. Refresh bait stations weekly until you stop seeing ant activity for at least two consecutive weeks.
Baiting is the most effective long-term solution because it eliminates the entire colony, not just the foraging workers you see indoors.
Use insecticidal dusts in hidden areas
Apply boric acid dust or diatomaceous earth directly into wall voids, attic spaces, and crawl spaces where you found frass or heard rustling sounds. Use a hand duster applicator to inject small amounts through existing holes or drill 3/16 inch holes near baseboards to access wall cavities. Dust particles stick to ants as they travel through treated areas and gradually dehydrate their exoskeletons over several days.
Target dust applications within 6 inches of confirmed or suspected nest sites for maximum impact. Wear a dust mask and safety glasses during application since these products irritate respiratory passages if inhaled.
Spray perimeter barriers
Apply a liquid insecticide spray in a 12 inch band around your home’s foundation, treating both the ground and the first foot of vertical wall surface. Focus on entry points you identified during inspection: cracks in concrete, gaps around pipes, and spaces beneath siding. Reapply the barrier every 60 to 90 days throughout the active season (spring through fall) to prevent new colonies from entering your property.
Prevent carpenter ants from returning
After you eliminate an active infestation, you need to implement long term prevention strategies to stop new colonies from establishing themselves on your property. Prevention focuses on making your home physically inaccessible and environmentally unsuitable for carpenter ants. These maintenance habits require minimal time investment but deliver permanent protection against re-infestation.
Create physical barriers
Seal all cracks and gaps in your foundation using silicone caulk or expandable foam. Pay special attention to areas where utility pipes, wires, and cables enter your home, since these create convenient highways for ants. Replace damaged weather stripping around doors and windows, and install door sweeps on exterior doors that have gaps larger than 1/4 inch.
Carpenter ants only need a 1/16 inch opening to access your home, so thorough sealing is critical for how to get rid of carpenter ants permanently.
Keep firewood stacked at least 20 feet away from your house and elevate it 6 inches off the ground on a rack. Remove tree stumps, rotting wood debris, and fallen branches from your yard since these provide ideal nesting sites for parent colonies.
Maintain a dry environment
Run dehumidifiers in basements and crawl spaces to keep relative humidity below 50 percent year round. Clean gutters quarterly and inspect your roof annually for damaged shingles or flashing that could allow water infiltration. Address any plumbing leaks within 24 hours of discovery to prevent moisture accumulation in wall voids or under floors.
Final thoughts and next steps
You now have a complete strategy for how to get rid of carpenter ants through inspection, treatment, and prevention. Most homeowners successfully eliminate infestations within two to three weeks using the baiting and dust methods outlined above. If you still see active ant trails after 30 days of treatment, or if you discover extensive structural damage, professional pest control delivers faster results. Contact Redi Pest Control for a free inspection and customized elimination plan that protects your home’s structural integrity.