Termite Treatment Options: DIY vs. Professional Solutions

Comparing Subterranean, Drywood, and Dampwood Termites: What You Need to KnowTermites are among the most damaging pests for homes and wooden structures worldwide. Though they share a common diet of cellulose, different termite groups have distinct behaviors, habitats, and signs of infestation. This article compares the three primary termite types that affect buildings—subterranean, drywood, and dampwood—to help homeowners recognize, prevent, and respond to infestations.

Overview: Three termite groups

• Subterranean termites live in the soil and build mud tubes to access wood. They are the most widespread and destructive in many regions.
• Drywood termites infest dry, sound wood above ground without needing soil contact; they often enter through furniture, timber, or structural gaps.
• Dampwood termites prefer wood with high moisture content and are usually found in decaying timber, stumps, or damp structural wood.

Each group differs in appearance, colony structure, feeding behavior, and the signs they leave behind, which affects detection and treatment strategies.

Appearance and colony structure

• Subterranean: Workers are pale and soft-bodied, soldiers have dark, rectangular heads with strong mandibles; colonies can be massive (millions), with a complex caste system and live mostly underground.
• Drywood: Generally smaller colonies (hundreds to thousands); soldiers and workers are usually darker and more robust than subterraneans; colonies live entirely within infested wood.
• Dampwood: Typically larger individuals and colonies than drywood but smaller than subterranean; soldiers often have elongated heads; colonies occupy very moist or decaying wood.

Reproductive alates (swarmers) for all types are winged and may look similar at a glance, but wing size, color, and the season of swarming can help differentiate species.

Habitat and moisture requirements

• Subterranean: Require soil contact and high humidity; construct mud tubes to bridge dry spaces and maintain moisture when feeding above ground on structural wood.
• Drywood: Do not require soil or extra moisture; can live inside dry furniture, beams, and studs. They thrive in drier environments and can survive in isolated wood pieces.
• Dampwood: Need high moisture content—often found in decaying logs, stumps, or buildings with chronic leaks or poor ventilation.

Because of these moisture needs, dampwood termites are less commonly the primary cause of severe structural damage in dry, maintained homes, but they can be serious where moisture problems exist.

Signs of infestation

• Subterranean:
  • Mud tubes on foundations, walls, or piers.
  • Hollow-sounding wood and sagging floors.
  • Frass (rarely visible; they push out soil particles).
  • Swarming alates near lights in spring or early summer.
• Drywood:
  • Tiny, hexagonal kick-out holes in wood.
  • Frass piles (coarse, pellet-like droppings) under infested wood or near windowsills.
  • Visible damage in isolated wood pieces or furniture; swarms often occur in late summer or fall.
• Dampwood:
  • Large galleries with smooth surfaces inside very wet wood.
  • Moist, decaying wood and dark staining from fecal matter.
  • Swarms typically near moist wood sources, often outdoors or in heavily damp structures.

Damage patterns

• Subterranean: Can cause widespread, concealed structural damage because colonies connect to many wood sources via soil and tubes; damage often extensive before detection.
• Drywood: Damage is localized to infested wood but can compromise structural members if undetected for long periods; because colonies are contained, treating one piece may not eliminate nearby colonies.
• Dampwood: Damage is focused where moisture persists; these termites accelerate decay but are usually limited to already weakened wood.

Detection methods

• Visual inspection for tubes, frass, swarmers, or wood damage.
• Tap or probe suspicious wood—hollow sounds or soft, crumbling sections indicate feeding.
• Use of moisture meters to find elevated wood moisture (helps locate dampwood activity).
• Canine detection and traps for flight intercepts may assist in locating subterranean or drywood activity.
• Professional inspections can include bait stations (subterranean) or structural probes and localized wood sampling.

Treatment and control options

• Subterranean:
  • Liquid soil treatments (barriers) and termite baits around foundations.
  • Localized spot treatments for galleries combined with barrier systems.
  • Fumigation rarely effective alone because colonies may be extensive; bait systems plus barriers are common.
• Drywood:
  • Whole-structure fumigation (tenting) is the most reliable for removing all colony members within a structure.
  • Localized treatments: heat, direct chemical injection into galleries, or freeze treatments for isolated infestations.
  • Removing and replacing heavily infested wood.
• Dampwood:
  • Repairing moisture sources and replacing decayed wood are essential.
  • Localized insecticide treatments or removal of infested material; fumigation is rarely necessary if infestations are outdoors or limited.
  • Improving ventilation, roof and plumbing repairs to prevent recurrence.

Integrated pest management (IPM) combines sanitation, moisture control, physical barriers, monitoring, and chemical or biological controls. For severe or uncertain infestations, consult a licensed pest control professional.

Prevention tips (by termite type)

• Subterranean:
  • Eliminate wood-to-soil contact; keep firewood off the ground and away from foundations.
  • Maintain proper grading and drainage; repair leaks and ensure ventilation in crawl spaces.
  • Install physical or chemical barriers during construction.
• Drywood:
  • Inspect secondhand furniture and structural timbers before bringing them inside.
  • Seal cracks and crevices in woodwork and attics to prevent alate entry.
  • Reduce moisture where possible but recognize drywood can persist in dry wood.
• Dampwood:
  • Fix leaks, replace rotted wood, improve ventilation, and remove dead wood near structures.
  • Keep gutters clear and ensure downspouts divert water away from foundations.

When to call a professional

• Visible structural damage, extensive mud tubes, or large swarms indoors.
• Repeated or uncertain detections after DIY treatments.
• When fumigation, bait systems, or large-scale structural repairs are being considered.

A licensed pest control operator can identify species, scope of infestation, and recommend targeted treatments and preventive measures.

Quick comparison table

Final notes

Understanding the differences between subterranean, drywood, and dampwood termites helps prioritize inspection, prevention, and treatment strategies. Moisture control and removing conducive conditions are universally important. For significant infestations or structural concerns, a professional inspection and treatment plan tailored to the termite type is the safest route.