Introduction
If you own a residential property or structure in North Carolina, it is nearly guaranteed that at some point, you will cross paths with the Eastern Subterranean Termite (Reticulitermes flavipes) – or at least with pest management companies recommending you treat your structure to protect it. These voracious structural pests will attack the wooden and other cellulose-based components (i.e., dry-wall) of a structure, potentially causing thousands of dollars in damages if left untreated. We have discussed the biology and behavior of these termites in a separate publication – Biology & Behavior of Eastern Subterranean Termites – but should you find yourself face to face with the small cream-colored destroyers of buildings, what do you do? In this publication, we discuss clear signs of termite activity, the professional treatment options available to you, and why it is always best to leave termite management to the professionals. After all, do you really want to gamble with your property? Read on to find out more!
Note: The information contained in this extension publication is relevant to North Carolina and may not be applicable to other states. Follow your own state’s regulations for termite management.
Signs of Termite Infestation
When considering the potential to have Eastern Subterranean Termites on your property, where do you begin? Do you need to wait until flying termites hit you in the face, or until a worker falls into your dinner plate? No, in fact there are several key signs worth recognizing that suggest a termite infestation and can indicate the need to involve professionals:
Swarmers
A termite colony can mature in 3-5 years and begin to produce reproductive swarmers (winged adults) (Figure 1). In North Carolina, we have at least three native species of subterranean termites that begin swarming in late winter and continue into September or October. Swarming usually occurs during the day, particularly on warm days following rain. Swarmers found outdoors near tree stumps, landscape timbers, etc., are not an indication that your house is infested, but they serve as a reminder that termites live around us. When swarming occurs indoors, it usually means that you have an infestation somewhere within your house. Several species of ants also swarm at the same times of the year as termites. Winged termites and ants look somewhat similar, but you can tell them apart by certain features (Figure 2). More information on termite swarmers can be found in our publication: Termite Swarmers: What Do They Mean For You?.
Mud Tubes
Unlike ants, termites do not roam around on the soil surface or out in the open. They will either tunnel through the soil or into wood (or other material) or travel inside small "mud tubes" that they build from soil, wood particles, and other materials (Figure 3). They do this for protection, but also to maintain the humidity of their environment. You can find these tubes on foundation walls, floor joists, or other parts of the house, hanging from sub-flooring, in cracks and crevices between structural members, or even within cellulose-based drywall and insulation. If found, break open the tubes to see if termites are still active, but remember that an empty tube doesn't necessarily mean that termites are gone. Termites regularly abandon tunnels and will rebuild those that become damaged. Old tubes are dry and crumble easily, leaving behind "etching" on the surface that may be visible for years (an indication that a house had termite activity at some time). Without knowing the inspection history of the house, it is impossible to tell or guess at the age of tunnels or etching.
Tubes that are found along ceilings or on upper levels of a building may indicate that you have an above-ground ("aerial") infestation, i.e., the termite colony actually lives in the building. This occurs when conducive conditions are present within the structure, such as leaking pipes or standing water that facilitate above-ground establishment. Mud tubes built by an aboveground colony usually contain materials other than soil, e.g., wood and dry-wall or whatever the termites are feeding on. In such situations, a thorough inspection may require removal of siding or interior wall boards, etc. More importantly for you, these aboveground infestations cannot be controlled with the usual soil treatment (see below) and are typically excluded from a termite contract warranty. In these situations, finding and correcting the moisture problem is the first step to eliminating the termites.
Damaged Wood
We tend to think of termites as feeding on or damaging wood only. Termites actually feed on almost anything that contains cellulose, the main component of wood, including wood paneling, paper products, cardboard boxes, art canvases, the paper covering of sheet rock, wooden picture frames, etc (Figure 4). While foraging and feeding, they may tunnel through non-cellulosic materials, such as plastic, foam board, and spray foam. More information on damage can be found in our publication: Biology & Behavior of Eastern Subterranean Termites. There is no accurate method for determining the age of recently discovered damage. You need some reference point, i.e., some point in time when it was known that there was no damage to this particular wood. This is one reason why annual inspections (and keeping your records of these inspections) are important. However, when inspecting, look for these signs of wood damage caused by subterranean termite feeding:
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Wood that sounds "hollow" when it is tapped with the handle of a screwdriver.
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Soft wood that is easily probed with a knife or screwdriver.
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A thin gritty gray-brown film on the surface of damaged material.
Figure 1. Eastern Subterranean termite alates - "swarmers" - preparing to take their mating flight.
Figure 2. Comparison of Termite & Ant Alates - with key features highlighted. Critical areas of difference are antennae, wings, and waist.
Figure 3. Mud tubes are on the side of a pillar in a crawlspace. These tubes are shelter for foraging termites, providing protection and moisture.
Figure 4. Termite damage on structural formboard. Termites can feed on any material that contains cellulose.
Monitoring & Prevention
One of the most effective methods of preventing a subterranean termite infestation is reducing conditions around your home that may be conducive to termites (Figure 5). Subterranean termites need a constant supply of moisture to survive, along with food (i.e., items containing cellulose). Even when structures are treated properly for termites, certain situations can occur that increase the potential for treatment failure. It is important to remain vigilant and address any issues promptly. Here are some examples of common conducive conditions for subterranean termites:
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The structure has not been treated for subterranean termites, which may increase the risk of infestation.
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Disturbance of the termiticide-treated soil band around a building can compromise its effectiveness. Avoid moving treated soil away from the foundation and covering treated areas with mulch, leaf litter, pine straw, or additional soil.
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Tampering with or removing installed termite bait stations. These can leave gaps in the monitoring and protective system around your structure.
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Direct contact between soil, mulch, or leaves and any wooden part of the house, siding, or insulation. This “wood-to-ground” contact provides an easy entry point for termites.
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Excessive water accumulating near the foundation or over-treated soil. This water can leach, dilute, or wash away the protective termiticide barrier, leaving the structure vulnerable to infestations. Common sources of excessive water include poor drainage systems or gutter downspouts that drain water too close to the building, leaky faucets or pipes, and excessive irrigation of lawns or flower beds near the foundation.
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Moist wood is one of the most significant conditions conducive to termite infestations. Moisture can originate from various sources, including roof leaks, improperly sealed flashing around chimneys or skylights, or damage to other structural components. Plumbing leaks and air conditioner condensation drips are also common culprits. Additionally, poor ventilation can lead to moisture condensation, particularly in crawl spaces or basements, further increasing the risk of infestation.
Subterranean termites may be monitored by looking for signs of an infestation (see above), using bait stations, or having a professional pest management company to perform a periodic inspection. Without a periodic inspection of your home, termite activity can remain undetected for years, placing your structure at higher risk for serious damage and increasing the potential financial burden of remediation.
Figure 5. A correctly sealed crawlspace, where moisture is greatly reduced but inspection gaps have been left for future use.
Continuous Termite Management
As a general rule, there currently are no reliable non-chemical methods of termite management. The only way to protect yourself and your structure is through colony elimination, and there are several chemical options available to consider. Here, we will discuss surveillance and baiting stations.
Termite surveillance and bait stations are designed to continuously monitor and manage termite colonies near and around built structures (Figure 6). Given the random foraging nature of subterranean termites, these stations are placed at fixed intervals around the perimeter of a structure to optimize the opportunity that foraging workers stumble onto it. To further encourage this, bait stations contain some form of wood- or compressed cellulose-type material that is ideal food for a termite colony. These stations can be loaded in one of two ways. They can be loaded with termiticide-free monitoring bait designed to entice termites, increasing the likelihood of identification upon subsequent inspection. Alternatively, bait stations can be pre-loaded with termiticide-containing baits, even if termite evidence has not been seen on the property. This decision is based in part on the bait stations installed and on the policy of the pest management company – be sure to discuss this with the company when establishing your termite contract.
Regardless of loading, all bait stations are used in the same general manner. They are installed at intervals of 10-20 ft around the structure and should be placed no further than roughly 2 ft away from the foundation wall. These stations are installed through the use of an augur (gas, electric, or manual) equipped with station specific bits. Holes are drilled in the ground roughly 6-12 inches deep. Prior to any drilling, it is critical to locate and mark any utility lines on the property. Once drilled, individual stations are pushed into the holes, loaded if necessary, and begin working immediately. Stations are typically checked every 3-6 months, depending on the company and product installed, and act as both an early warning sign and management strategy for termites.
What if termites still make it to your structure? Have this conversation with the company you have selected prior to establishing the termite contract to make sure you are aware of their specific procedures. In general, there are several options:
Liquid Treatment: Often if termites are found to have passed the bait station barrier and made it onto the structure, companies will provide a spot-liquid termiticide treatment of the affected area (see below). The cost of this varies depending on the company, and may be included in your contract. Be sure to discuss this.
Above-Ground Stations: Some companies produce above-ground bait stations, which act in a similar way to those installed around the structure, but instead can be installed directly onto areas of termite activity (Figure 7). These stations contain cellulose-based material laced with termiticide. This provides the foraging termites with a readily available toxic food source and will ultimately eliminate the colony given enough time.
Figure 6. A pest management professional inspecting a termite bait station.
Figure 7. One example of an above ground termite bait station.
Liquid Termiticide Treatment
The Basics of Treatment
An often relied upon alternative to continuous termite management systems is to apply a liquid termiticide chemical barrier around (and sometimes underneath) the structure. Simply spraying insecticide on swarmers or the surface of accessible infested wood may kill the termites that you see now, but it does not stop the infestation nor does it protect your house from future attacks by termites. The most common type of termite treatment is a soil treatment in which a liquid insecticide (termiticide) is applied to the soil surrounding critical areas of your house (Figure 8).
The most critical treatment area is the foundation wall, as this is often the first area of the home encountered by foraging termites. However, the “foundation” of a structure runs far deeper than what is seen on the surface. As such, prior to liquid application the soil surrounding the exterior foundation wall is trenched 6" deep and about 4-6" wide. For houses with crawl spaces, the soil along the interior foundation wall is also trenched (in the same manner), as well as the soil around foundation supports such as pillars and piers. In cases where there are dirt-filled porches, they must either be accessed and treated from the crawlspace, or drilled and rodded (vertically or horizontally). In addition, walkways and driveways preventing the trenching of soi must be drilled, and liquid flooded under the slabs via rodding. Within garages the cement or expansion joints must also be drilled and rodded. If termite evidence is found along the foundation wall, all voids within 4 feet of identified signs of termite activity must be drilled and treated as well (Figure 9). In order to be effective, this treatment must extend down through the soil to the top of the foundation footer. When applied correctly, this treatment forms a continuous chemical barrier that should prevent termites from reaching the foundation and piers in your house, and will last for many years. Be sure to maintain the termite contract for additional protection.
In the case of slab or basement constructions, exterior foundation walls are trenched and treated in the same manner as for crawl space constructions. However, interior slabs are either drilled (in the case of unfinished slab) or often “waived” by the company (in the case of finished floors that would be damaged). Discuss this with the company of your choosing prior to signing the treatment contract to better understand your specific situation.
Additional Points
Current North Carolina regulations also require drilling and treating of:
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Concrete slabs that attach to the house, for example, a garage floor, or the slab of an earth-filled porch.
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Voids inside foundation walls, piers, etc. within 4 feet of known termite activity. Some pest control companies still drill and treat the entire foundation wall and piers.
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The side walls of earth-filled porches within 3 feet of the foundation wall and any structural wood.
You can view the state regulations or obtain a copy from the North Carolina Department of Agriculture & Consumer Services - Structural Pest Control and Pesticides Division (NCDA&CS) in Raleigh. These specifications are the current minimum requirements for a treatment under state regulations.
Spot Treatments & Waivers
Some companies offer "spot treatments", i.e., they treat only the area(s) of the house where termites are found. A spot treatment may seem like a good idea because it costs less than a full treatment; however, there are some important risks to remember. First, a spot treatment may not actually correct the problem. The area where termites were discovered may not be the colony, and so while you may kill some termites your structure could still be at risk. Second, except when done under an existing contract, a spot treatment often carries a very limited guarantee (or no guarantee at all). It's your structure, your money, and your choice. Don't let economics be your only determining point about how to protect your property from termites.
On a new termite contract, any treatment procedures that will not be done according to NC regulations must be noted on an official Waiver of Minimum Standards form. You must sign this form as part of your contract. If you are asked to sign a waiver form, make sure you understand what each waived item means (i.e., what work is not being done and why it is not being done). Discuss these decisions with the company to better understand the risks involved with not having these procedures performed.
Regardless of whether you have a liquid termite treatment or a baiting system installed, remember this important point: Before you sign a service agreement or contract, read it carefully. Here are some questions to help you evaluate the proposed service:
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How will the treatment be done?
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Does the proposed treatment require a waiver? If so, what treatment specifications will not be done? Why aren't they being done?
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What type of guarantee is included under the contract? Some contracts offer a "retreatment-only" guarantee. If there is a repair guarantee, what is or is not covered by the guarantee?
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Does signing any waiver form affect the guarantee in any way?
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What are the terms for renewing or maintaining the contract?
Why not "Do-it-Yourself"?
Although there are termiticides available for homeowner use, we do not recommend the "Do-it-Yourself" (DIY) approach for chemical control of termites for several reasons. Termites are complex insects with challenging behaviors and colony structure – termites in one area doesn’t mean they aren’t somewhere else. Only a thorough inspection, by a trained expert, can show if the termites are also feeding other places and even then, termites could be infesting your home in areas that are inaccessible, and therefore, uninspectable. Also, simply spraying the soil surface and/or exterior foundation wall is not going to stop a termite infestation below ground and possibly entering your home from below ground. Given this, there are a slate of things that you as the home- or business owner would need to be able to do in order to treat your property yourself:
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You must trench and treat the soil along the foundation wall, externally and internally (crawl space) and on all sides of piers. The trenches must be 4-6 inches wide and 6 inches deep, depending on the depth of your foundation's footer. Your crawlspace is confined, and at times incredibly challenging to trench.
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Most pesticide labels require pesticide applicators working in confined spaces, such as crawl spaces, to wear specific personal protective equipment, such as a cartridge-type air filtering respirator (not simply a dust filtering mask) and other personal protective equipment.
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You need a substantial volume of diluted chemical and a rig able to apply that chemical at the correct volume. Most termiticides are applied to the soil at the rate of 4 gallons per 10 linear feet per foot of footer depth (i.e., the depth from the soil surface down to the top of the foundation footer). Most footers in eastern and central North Carolina are about 12-18 inches below grade (soil level). Therefore, as an example, a house that has a 40 ft x 30 ft "footprint" (120 linear feet) and a one-foot deep footer would require 48 gallons of termiticide spray just to treat the soil along the outside foundation wall. The total amount of chemical needed will depend on whether the interior foundation wall needs to be treated (in part or all of it) and on other aspects of the building construction (such as attached garage slabs, earth-filled porches, etc.) but could easily exceed 100 gallons. Houses with basements or those built on slopes may have deeper footers and so you would also need the equipment to treat to the necessary depth, which could be as much as 4 feet. Few homeowners have the equipment to mix and apply large quantities of chemicals properly and safely.
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You would need a sizable drill to punch through concrete slabs (such as porches and garages) as well as voids in foundation walls and piers that are adjacent to the termite infestation. This part of the treatment requires some understanding of construction, in addition to specialized equipment and training to avoid injuries or damage to underground utility lines or to masonry. Although you could omit this part of the work, an incomplete treatment may not solve the problem and may leave your house vulnerable to continued or future termite attack.
These are just a few examples of why DIY treatments for termites are a bad idea. In summary, leave it to the professionals and rest knowing that your structure, your finances, and your peace of mind are well taken care of.
Figure 8. A pest management professional performing a perimeter soil treatment using liquid termiticide.
Figure 9. Drilling of voids within 4ft of termite evidence along a foundation wall.
Publication date: Jan. 22, 2025
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