Termites

Identifying the termite species on your property determines the treatment protocol, so accurate identification matters. Subterranean termites (genus Reticulitermes in most of the country, Coptotermes formosanus in the Gulf South and Hawaii) are the nationwide default — cream-colored workers about 1/8 inch long, with dark-brown reproductive swarmers that drop their four equal-length wings after mating flights. Subterraneans require contact with soil moisture and build distinctive pencil-width mud tubes along foundations, piers, and exposed joists.

Drywood termites (genus Incisitermes) are larger, tan to dark brown, and live entirely inside the wood they consume. They do not require soil contact, which makes them common in attics, eaves, and wooden furniture in Florida, the Gulf Coast, California, Arizona, and Hawaii. The telltale sign is six-sided fecal pellets, called frass, accumulating below small kickout holes in infested wood.

Dampwood termites (genus Zootermopsis) are the largest of the three — reproductives can exceed an inch in length — and attack decaying or moisture-damaged wood in the Pacific Northwest, Northern California, and higher-elevation mountain regions. They rarely infest sound structural wood, making them less common in homes but serious in outbuildings and fallen lumber.

Formosan subterranean termites deserve special mention: an invasive Asian species established across the Gulf Coast and South Carolina, their colonies can exceed several million insects and can attack structures 300 feet from the soil nest. If you live along the Gulf Coast and see termite activity, assume Formosan until proven otherwise and call a professional immediately — DIY treatment almost never works against a Formosan colony.

Understanding the termite lifecycle helps homeowners time inspections and recognize early-warning signs. A new colony begins when winged reproductives (alates) emerge from an established colony during spring or early-summer swarming flights. Most die within hours, but surviving pairs shed their wings, find a crevice in wet soil or wood, and begin a new colony.

The queen lays eggs for her entire 25-to-50-year lifespan. For the first two to four years, the colony is small (a few hundred workers) and causes no visible damage. Between years three and five the colony matures, produces its first generation of swarmers, and damage accelerates. A mature subterranean colony typically holds 60,000 to 1 million workers; a mature Formosan colony can exceed several million. Each worker lives only one to two years but the caste system regenerates continuously.

For homeowners, the practical implication is that by the time you see swarmers inside your house or discarded wings on a windowsill, the responsible colony has been on your property for three to five years already. That is also why damage often looks sudden even though the underlying feeding has been continuous — termites hollow wood from the inside out, leaving the painted exterior intact until the remaining shell gives way under load.

Termite pressure varies dramatically by region, and the correct treatment depends on which species dominates your area. The University of Arkansas Division of Agriculture publishes a Termite Infestation Probability Zone map that divides the country into four tiers.

Zone 1 (very heavy) covers the Gulf Coast from East Texas through Florida and up the Atlantic seaboard to southern Virginia, plus Southern California, Arizona, and Hawaii. Annual inspection is non-negotiable; most lenders in these zones require a termite bond for purchase.

Zone 2 (moderate to heavy) covers the remaining Southeast, the lower Midwest, the Southwest, and the coastal Pacific Northwest. Biennial inspection is the floor; annual is better for homes over twenty years old or with known past activity.

Zone 3 (slight to moderate) covers the upper Midwest, Mid-Atlantic inland regions, and interior mountain states. Inspect every two to three years and treat preventively when remodeling or adding new wood features.

Zone 4 (none to slight) is limited to high-elevation and cold-climate regions: interior Alaska, northern Maine, and mountain ecoregions above the termite tree line. Inspection is still recommended every five years because imported wood products occasionally translocate colonies.

If you are unsure of your zone, the simple rule: if your ZIP code experiences fewer than twenty days below freezing per year, treat as high-risk.

DIY termite treatment has a narrow but real place. For a small, contained drywood infestation in a piece of furniture, an exposed deck joist, or a visible kickout hole in an attic beam, borate wood treatments, foam injections, and spot heat treatment can work. Over-the-counter borate products from hardware stores run $30-$100 and, applied correctly to exposed wood, both kill active insects and prevent reinfestation.

DIY fails predictably against subterranean colonies. The colony lives in the soil, not the wood; killing the workers you can see does not reach the queen. Liquid barrier chemicals purchased over-the-counter are also formulated below professional-grade concentrations because federal law restricts the stronger termiticides to licensed applicators. You can exhaust several hundred dollars on retail product and achieve nothing but a temporary reduction in visible workers.

Professional treatment is the correct default for any active subterranean or Formosan infestation, any drywood infestation that is not obviously isolated, and any new home purchase where a termite letter is required. Expect a full inspection ($75-$150, often credited toward treatment), a choice between liquid termiticide barrier ($1,200-$2,500) or in-ground bait stations ($1,200-$3,500 with first-year monitoring), and a written guarantee typically running one to five years. Fumigation for a whole-structure drywood infestation runs $1,200-$4,000 and requires two to three nights out of the home.

One hybrid approach works well: hire a licensed inspector annually, keep the bond current for liability coverage, and handle spot drywood issues with borate or foam treatments yourself between visits.

The numbers that usually shock homeowners most are not the treatment costs but the repair costs after a delayed diagnosis. A routine termite inspection is $75-$150. A full treatment on an active colony runs $1,200-$3,500. But structural repairs after three to five years of undetected damage — replacing subfloors, sistering joists, re-sheathing exterior walls, rebuilding sill plates — routinely exceed $10,000 and can pass $30,000 on older homes or homes with mature Formosan infestations.

Because homeowners insurance explicitly excludes termite damage under nearly every standard policy, those repair costs come out of pocket. A few specialty insurers offer termite damage riders for $100-$300 per year, but they require an active termite bond and pre-inspection. For most homeowners, the math is straightforward: the annual inspection pays for itself the first time it catches early activity, because catching a colony at year two instead of year five changes the bill from $30,000 in repairs back to $2,000 in treatment.

If you are buying a home in a Zone 1 or Zone 2 area, ask specifically whether the seller has maintained a termite bond, pull the history on any prior treatments, and do not waive the termite inspection during closing. A clean inspection report protects both the purchase price and the first year of ownership.