How do you know if you have a carpenter ant nest?

Carpenter ants are large black ants common in many parts of the United States that can cause significant damage to wood in homes. A carpenter ant infestation can be a major nuisance and lead to structural damage if left untreated. Knowing the signs of carpenter ants and inspecting your home regularly can help you identify an infestation early and take steps to eliminate it. Here are some of the key things to look for to determine if carpenter ants have made a nest in your home.

Sawdust-like material around the house

One of the most common signs of carpenter ant activity is the appearance of small piles of sawdust-like material around your house. As carpenter ants tunnel into wood to make their nests, they leave behind bits of chewed wood. You may see little piles collecting around baseboards, windowsills, door frames, attics, or crawl spaces where the ants have been excavating. This frass, or insect waste, will look like very fine sawdust. The presence of these wood shavings is a clear indication you likely have an active carpenter ant colony nearby.

Small black ants

While foraging carpenter ants may occasionally come into view around the home, locating the nest itself can be more challenging. Carpenter ants aren’t attracted to food spills and sweets like some other ant species. However, you may catch glimpses of them crawling along walls or baseboards as they travel to and from the nest. Carpenter ants range from 1/4 inch to 3/4 inch long. They are shiny black with evenly rounded segments on the abdomen. Seeing these large black ants moving along wood surfaces or emerging from tiny cracks is a warning sign a nest may be hidden behind walls or under insulation.

Muddy trails

Carpenter ants create well-worn foraging trails they use to commute to and from food sources. Outdoors, you may notice smooth muddy trails leading up the side of your home’s foundation or across patio stones, especially after a rain. The ants use these trails constantly, keeping them clear of debris. Finding converging wide trails around your property could indicate a carpenter ant colony has become established. Trails often lead back to prime nesting spots like rain gutters, fences, tree stumps, or decking.

Wood damage

One of the most definitive ways to confirm the presence of carpenter ants is visible wood damage. As carpenter ants tunnel and expand their nests, they can cause significant destruction to wooden structural elements in a home. Damaged materials may have irregular holes bored into them or a honeycomb-like appearance. Ants often nest in wet, rotting wood. Look for sections where wood seems splintered, compromised, or sagging. Window frames, roofs, decks, and untreated timber may show the first signs of carpenter ant infestation through this wood deterioration.

Nocturnal activity

Carpenter ants are most active at night. If you suspect you may have carpenter ants in your home’s walls or attic space, inspect these areas after dark when the ants are busy foraging. Use a flashlight to examine crawl spaces, baseboards, ceiling corners, and insulation for signs of ants traveling along their preferred pathways. Listen for the faint sounds of antennae tapping or ants gnawing on wood within walls or floor voids. Disturbing the ants’ trails may prompt them to investigate by squeezing through tiny crevices temporarily. The more ants emerge, the larger the nest size.

Winged ants inside

From late spring through summer, carpenter ant colonies produce winged reproductive ants that emerge in swarms to mate and establish new nests. If you notice large black winged ants with a single node between the thorax and abdomen inside your home, it likely means an existing mature carpenter ant colony is located nearby. Swarming ants can pinpoint nest locations as they gather by windows and doors before flying outside. Seeing winged carpenter ants emerge from cracks in walls or wood is a clear sign those areas contain a hidden nest.

Signs of water damage

Because carpenter ants desire moist wood to excavate their nests, areas with existing water damage or leaks can be prime real estate. Inspect any parts of your home’s exterior like roofs, windows, siding, or decks that could allow moisture intrusion. Look for swollen, cracked, moldy, or rusty wood that indicates rainwater or plumbing leaks. Carpenter ants are also attracted to wet, rotting wood. Trace water stains or damp areas back to their source to hone in on where ants may be nesting in adjacent wood.

Muddy or straw-like piles near foundation

Carpenter ants excavate wood to make room for their large nests, pushing out debris through tiny cracks and crevices. You may notice growing piles of fine soil accumulating near the home’s foundation as ants continually remove excavated bits of nesting material. This loose debris looking like mud or straw can collect under doors or windows, in crawl spaces, or under siding. Piles of earth appearing randomly along the foundation or anywhere carpenter ants can access from their nests offer a clue to tracking down the infestation.

Rustling sounds in walls

An active carpenter ant nest inside a wall void sounds like a light rustling or ticking as the ants move about and interact. If you observe sawdust piles below an electrical outlet, along the tops of baseboards, or in cracks where wires enter the wall, press your ear against the wall to listen. The sounds of carpenter ants can often distinguish them from other household pests taking up residence within walls. Being able to pinpoint the location helps focus treatment efforts on areas housing the nests.

Small holes in wood structures

Carpenter ants don’t consume wood like termites. However, mature colonies carve out sizeable cavities in softer woods to serve as their central nesting site. As ants widen passages to expand the nest to accommodate growth, tiny round holes may become visible, especially along the grains in wood. Look for a cluster of small holes about 1/8 inch in diameter in fence posts, trees, landscaping timbers, or other weathered wood around the property. The holes won’t penetrate deeply but can provide an entry point to track down the nest location.

Carpenter ants in trees

Carpenter ants frequently nest in trees, logs, or stumps in wooded areas. Inspect trees near your home for signs of carpenter ant activity. Look for trails of ants crawling up and down the bark, particularly around tree crevices or hollows. Knocking on the trunk can disturb the ants and prompt them to pour out of nesting voids. Also check for small holes scattered across the tree surface and sawdust buildup accumulated in branch junctions or where limbs meet the trunk. Dead trees and those damaged by lightning or disease are prime targets for carpenter ants to move in.

Ants near moist or rotten wood

Carpenter ants have a strong attraction to wood made moist and soft from water damage, mold, or decay. Take note of any locations around the exterior of your home where wood has remained damp and begun deteriorating. Crawl spaces, attics, rotten fence posts, decking softened around nails, or wood discolored by water leaks are prime locations. Focus your inspection on these high-probability areas. The presence of ants traveling to and from moist wood is a good sign their nest is nearby within the compromised section.

Antennae protruding from cracks

Once you zero in on a section of wall or wood where you suspect carpenter ants are nesting inside, watch for antennae peeking out from cracks and crevices. Indoors, seek out tiny spaces where baseboards meet walls, electrical conduit exits walls, heat vents enter floors, or anywhere wires and pipes penetrate wood framing. Outdoors, examine spaces where sections of siding, roof tile, or trim boards meet. If you disturb the ants’ activity, they may rush to investigate by poking antennae and heads partially out in search of the cause of the disruption. Focus your inspection and treatment in areas where ants appear from inside voids.

Frequent ant sightings after rain or at night

Carpenter ant activity increases during certain times of day and after weather events. Take note if you notice more carpenter ants crawling along walls, trailing along floors, or flying around indoors at night or after periods of heavy rainfall. Ants may be disturbed from their nesting areas within walls and wood structural voids during these times. Increased ant sightings when conditions prompt them to move their brood could signify sizable colonies warranting inspection. Combining your observations during these peak activity periods can help confirm and pinpoint infestation areas.

Wood inspection

If you have an unfinished basement, storage attic, crawl space, or means to access other areas behind walls, physically inspect exposed wood for carpenter ant damage. Use a screwdriver to poke into softened, damp wood materials and rotten logs. Shine a flashlight into dark corners and crevices. Disturb woodpiles stored against foundations. Carpenter ant tunnels may be found hidden within insulation or burrowed into the undersides of floors. Visually checking suspect wood around the property both inside and out provides confirmation ants have invaded these areas.

Follow ants to their trails

One technique to locate hidden nesting areas is tracing ants back to their trails and food sources. Indoors, firmly tap on walls, baseboards, or wood trim where you have noticed sawdust piles or ants traveling. Disturbing their pathways prompts the ants to leave the nest in search of the cause. Follow individual ants to observe where they enter cracks, voids, or crevices. Outdoors, a similar process of disruption near suspected nesting sites like trees, stumps, and poles reveals where ants retreat back to. Take note of these areas to target treatment.

Call in the experts

If careful inspection of your home fails to reveal the location of carpenter ant nesting areas, yet the signs of infestation persist, it may be wise to enlist the help of professional pest control experts. An exterminator can employ special detection methods to pinpoint hard-to-find nesting sites. Infrared cameras can identify moisture intrusion and differences in wood density. Acoustic detectors can pick up the sound of carpenter ant movement within voids. Wall void inspection uses tiny borescope cameras. Getting an exact fix on nest locations ensures a targeted treatment approach for complete removal.

Conclusion

Carpenter ants are capable of doing extensive damage to wood structures if their colonies go unnoticed and untreated. Left unchecked, a serious carpenter ant infestation can even compromise the integrity of a home’s support structure. Catching these insects early not only prevents costly repairs but also limits the ants’ opportunity to multiply and spread to other areas in the surrounding landscape. Being vigilant for the common signs of carpenter ants and inspecting vulnerable areas both inside and outside the home increases the chances of finding and destroying nests promptly. If monitoring and targeted treatment efforts prove ineffective, seeking professional pest control assistance can pinpoint elusive nest locations. Stopping carpenter ants quickly protects your home and prevents major headaches down the road.