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Termites

Signs of termite damage

Termite infestations can go undetected for years, hidden behind walls, floor coverings and insulation, because the outer surface of the wood usually stays intact.[2]

The short answer

  • Pencil-wide mud tubes on the foundation, piers, sill plates or joists are the most common sign of subterranean termites.[1][2][3]
  • Subterranean termite damage is hollowed out along the grain, with bits of dried mud or soil lining the galleries.[2][3]
  • Drywood termites leave piles of six-sided fecal pellets below small kickout holes.[4]
  • Swarmers or shed wings on windowsills and along floors.[3]
  • Damaged wood proves termites are there now or were there in the past. On its own it can't tell you which, and no method can date when the damage happened.[7][9][8]
  • Termites damage wood slowly. NC State says serious damage usually takes about 3 to 8 years, so there is time to get inspections and compare bids.[9][2][8]

Mud tubes

Workers build shelter tubes from soil, saliva and bits of wood to travel between the soil and wood without drying out. Break one open: live, creamy-white workers mean it is active.[1][2]

UC IPM describes four kinds: working tubes from soil to wood, exploratory tubes that don't reach wood, drop tubes from wood back to soil, and swarm tubes used at swarming time.[1]

An empty tube doesn't prove the termites are gone; they may have abandoned that one tunnel. Termites often rebuild a tube that has been broken, which is another sign they're still active.[9]

Tubes on ceilings or upper floors can mean the colony is living above ground inside the building, a moisture-fed infestation that the usual soil treatment won't control.[9][5]

What damaged wood looks like

Subterranean termites eat wood from the inside and leave the surface in place, so the damage is easy to miss. The excavations are hollow, closed-in cavities that run mostly lengthwise along the board.[1][2]

  • Darkening or blistering of structural wood that is thin at the surface and easy to puncture with a screwdriver.[1]
  • Subterranean termites eat the softer springwood and leave the harder summerwood, a pattern that can distinguish them from other species; Formosan termites eat both.[1][5]
  • Tiny holes through drywall or plaster with bits of soil around the edge, or rippled or sunken areas behind wall coverings.[2]
  • Wood that sounds dull or hollow when tapped, even under paint.[5]
  • Mud or soil inside the galleries. Subterranean termites carry moist soil into the wood they infest, and Texas A&M says shelter tubes plus mud in the galleries point to an active infestation. Kansas State adds that the galleries are not always occupied when you open them.[7][2][8]
  • Mud-filled joints in wood framing, paneling and trim in finished rooms.[8]
  • A thin, gritty, gray-brown film on the surface of the damaged material.[9]
  • Wood that is soft and easy to push a knife or screwdriver into.[9][8][10]

Where damage hides

Most homeowners don't know they have subterranean termites until something forces the issue: an inspection for a home sale, damaged wood found during a remodel, a shelter tube on a wall, or thousands of winged insects coming out in a kitchen or bathroom.[13][10]

  • Behind paint and wall coverings. Look for blistering in paint or wallboard, and for rippled or sunken lines where termites tunneled underneath.[5][2]
  • In materials other than wood. Termites feed on almost anything with cellulose, including paneling, cardboard, books, insulation and the paper facing on drywall, and they tunnel through plastic and foam board on the way.[9][2]
  • Formosan termites chew through asphalt, plaster, rubber and plastic while searching for food and moisture. Texas A&M says their damage can cause house fires through electrical shorts.[5]
  • Formosan colonies can build carton nests (chewed wood, soil, saliva and fecal material) inside wall spaces when moisture is available, and keep feeding there even if cut off from the soil.[5]
  • Weak or broken structural members, blistered wood and soil in cracks are other signs the Texas Department of Agriculture lists for subterranean termites.[11]

Drywood and dampwood termite damage

Drywood termites live inside the wood and don't need soil. They eat both the soft springwood and the harder summerwood, so their galleries look smooth and sculptured and cut across the grain, with fecal pellets in the chambers.[15][13]

  • Kickout holes: UC IPM says these are small, under 2 mm across, and the termites push pellets out through them.[14]
  • Pellets: about 1/32 inch long, the color of the wood they came from, with six sides or lengthwise ridges you can see under a magnifier.[15][14]
  • Surface blisters on wood, and shed wings or piles of droppings that look like sawdust on windows and floors.[11]
  • Pellets alone don't show whether the infestation is still active or how far it goes. UC IPM suggests sweeping up the pellets under a kickout hole and checking a few days later for new ones, while noting that building vibration can shake a few old pellets loose.[14]
  • Dampwood termites make large, open galleries in moist, decayed wood. Their pellets are rounded at both ends and lack the clear ridges of drywood pellets.[1][14]

Damage that isn't termites

Carpenter ant galleries are smooth and clean with coarse, fibrous sawdust pushed out nearby; wood damaged by moisture alone lacks the soil-lined galleries of subterranean termites.[6][2][16]

Dampwood termites infest decayed, moist wood and point to a moisture problem.[1]

  • Carpenter ants: they hollow out wood to nest but don't eat it. Their galleries are smooth-sided with no soil or fecal pellets, and piles of coarse, stringy shavings mixed with dead insect parts sift out of cracks and behind moldings. They seldom tunnel into dry, sound wood and prefer moist or rotting wood.[16][17]
  • Powderpost beetles: small round exit holes with flour- or talc-like powder in small piles beneath them. Penn State gives hole sizes of about 1/16 to 1/8 inch; NC State says 1/32 to 1/16 inch. Kentucky Extension says powderpost beetles are second only to termites in damaging dry, seasoned wood.[18][19][20]
  • Telling beetle powder from termite pellets: powderpost frass is fine and dusty, while drywood termite pellets are larger and granular, almost like pepper, with ridges on the sides.[21][15]
  • Carpenter bees: a nearly perfectly round entrance hole about 1/2 inch across, often in unpainted, weathered wood such as eaves, railings and windowsills. The tunnel turns at a right angle about an inch in and runs with the grain, with coarse sawdust and stains from bee droppings below the hole.[22][23]
  • Brown rot: decaying wood darkens, shrinks and twists, cracks form across the grain, and it eventually turns dry and powdery. White rot leaves wood bleached, fibrous and spongy. NC State says wood saturated to 30 percent moisture will rot, and these fungi stop growing below 20 percent.[20]
  • Mold, mildew and blue, black or gray sapstain mean the wood has been wet, but they don't weaken it.[20]

Old damage or an active infestation?

The sources agree that the age of damage can't be pinned down. Texas A&M calls it virtually impossible, Kansas State says you can't tell how long galleries have existed, and NC State says you need a reference point, a time when the wood was known to be undamaged, which is why it recommends keeping records of past inspections.[7][8][9]

  • Signs of current activity: live workers in a freshly opened tube, tubes that get rebuilt after you break them, and swarmers emerging indoors.[2][9][3]
  • For drywood termites, new pellets after a cleanup are the practical test.[14]
  • For powderpost beetles, NC State says frass that is yellow and caked is usually old and likely from an infestation that is no longer active.[20]
  • Contracts matter here. NC State says damage found behind a wall with no termites present is usually treated as existing damage and excluded from a repair guarantee, because nobody can show when it happened. Kentucky Extension says the same problem complicates companies that offer to repair damage after their treatment.[9][2]

How fast termites do damage

Slowly. Kansas State says a mature colony eats only about one fifth of an ounce of wood a day. NC State cites research that a colony of 60,000 workers could eat one foot of a 2 x 4 in slightly over 5 months, and puts serious damage at about 3 to 8 years in practice.[8][9]

Formosan termites are the exception to keep in mind. They eat both springwood and summerwood, and Mississippi State says they can do more damage in a shorter time than eastern subterranean termites.[5][12]

Texas A&M estimates that an unprotected home there has about a 70 percent chance of some termite damage within 25 years.[7]

Confirming it

Confirmation often needs a professional, and even an experienced inspector can miss hidden signs. Inspections from more than one company help verify an infestation.[2]

Taking an extra day, week or month to decide generally makes no real difference to the amount of damage. NC State suggests calling two or three companies if you don't have a termite contract.[2][9][8]

  • A termite inspection report is not a structural report. The Texas Department of Agriculture says a wood-destroying insect inspector isn't expected to judge the extent of structural damage.[11]
  • NC State suggests asking whether any damage should be repaired, or at least looked at by a contractor or engineer, before treatment begins.[9]
  • If the damaged wood is load-bearing, UC IPM says to consult an architect, engineer or general contractor, and building permits may be needed.[14]
  • If you file a complaint with the Texas Department of Agriculture about a termite treatment, it advises against repairing the damage or having the home treated before its inspector has investigated.[11]

Common questions

Does termite damage mean I still have termites?
Not necessarily. Damaged wood shows termites are there now or were there before. Look for live workers in tubes, rebuilt tubes or indoor swarmers, and have a professional inspect.[7][9][2]
Can someone tell how old termite damage is?
No. Texas A&M, Kansas State and NC State all say there is no reliable way to date it, which is why records of past inspections matter.[7][8][9]
How do I tell termite damage from carpenter ant damage?
Termite galleries have mud or soil packed in them; carpenter ant galleries are smooth and clean, with coarse shavings pushed out nearby.[2][16][17]
Is it termites or powderpost beetles?
Powderpost beetles leave small round exit holes with fine, flour-like powder. Subterranean termites leave soil-lined galleries, and drywood termites leave hard, ridged pellets.[18][21][2][15]

Checking and treating

Next steps once you think you've found termite damage.

Sources

  1. University of California Statewide IPM Program, “Pest Notes: Subterranean and Other Termites, Publication 7415 (May 2014).” ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pntermites.pdf (accessed 2026-10-06)
  2. University of Kentucky Entomology, “ENTFACT-604: Termite Control: Answers for Homeowners (revised March 2026).” entomology.mgcafe.uky.edu/ef604 (accessed 2026-10-06)
  3. University of Kentucky Entomology, “ENTFACT-605: Protecting your Home Against Termites (revised March 2026).” entomology.mgcafe.uky.edu/ef605 (accessed 2026-10-06)
  4. University of California Statewide IPM Program, “Pest Notes: Drywood Termites, Publication 7440 (August 2014).” ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pndrywoodtermites.pdf (accessed 2026-10-06)
  5. Texas A&M AgriLife Extension, “Formosan Subterranean Termites, E-367.” extensionentomology.tamu.edu/wp-content/uploads/sites/3/2017/01/Formosan-subterranean-termites-E367.pdf (accessed 2026-10-06)
  6. University of California Statewide IPM Program, “Pest Notes: Carpenter Ants, Publication 7416 (August 2009).” ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pncarpenterants.pdf (accessed 2026-10-06)
  7. Texas A&M AgriLife Extension, “Subterranean Termites, E-368 (R.E. Gold, K.M. Schofield, E. Brown and M. Keck, 9/10).” extensionentomology.tamu.edu/wp-content/uploads/sites/3/2017/01/Subterranean-termites-E368.pdf (accessed 2026-11-10)
  8. Kansas State University Agricultural Experiment Station and Cooperative Extension Service, “Termites, MF-722.” bookstore.ksre.ksu.edu/pubs/MF722.pdf (accessed 2026-11-10)
  9. NC State Extension, “Termites: Biology and Control.” content.ces.ncsu.edu/termites-biology-and-control (accessed 2026-11-10)
  10. U.S. Environmental Protection Agency, “Termites: How to Identify and Control Them.” www.epa.gov/safepestcontrol/termites-how-identify-and-control-them (accessed 2026-11-10)
  11. Texas Department of Agriculture, “Termite FAQs (Structural Pest Control Service).” texasagriculture.gov/Regulatory-Programs/Pesticides/Structural-Pest-Control-Service/Termite-Fumigation-Applications/Termite-FAQs (accessed 2026-11-10)
  12. Mississippi State University Extension, “Species of Termites in Mississippi.” extension.msstate.edu/insects/termites/species-termites-mississippi (accessed 2026-11-10)
  13. University of California Statewide IPM Program, “Pest Notes: Subterranean and Other Termites, Publication 7415 (web edition).” ipm.ucanr.edu/home-and-landscape/subterranean-and-other-termites/ (accessed 2026-11-10)
  14. University of California Statewide IPM Program, “Pest Notes: Drywood Termites (web edition).” ipm.ucanr.edu/home-and-landscape/drywood-termites/ (accessed 2026-11-10)
  15. Texas A&M University, Urban and Structural Entomology Program, “Drywood Termites.” urbanentomology.tamu.edu/urban-pests/termites/drywood/ (accessed 2026-11-10)
  16. University of Nebraska-Lincoln Extension, “Carpenter Ant Management, NebGuide G1738 (revised August 2019).” extensionpubs.unl.edu/publication/g1738/na/html/view (accessed 2026-11-10)
  17. Penn State Extension, “Carpenter Ants.” extension.psu.edu/carpenter-ants (accessed 2026-11-10)
  18. University of Kentucky Entomology, “ENTFACT-616: Powderpost Beetles.” entomology.mgcafe.uky.edu/ef616 (accessed 2026-11-10)
  19. Penn State Extension, “Powderpost Beetles.” extension.psu.edu/powderpost-beetles (accessed 2026-11-10)
  20. NC State Extension, “Powderpost Beetles and Wood-Inhabiting Fungi.” content.ces.ncsu.edu/powderpost-beetles-and-wood-inhabiting-fungi (accessed 2026-11-10)
  21. University of California Statewide IPM Program, “Pest Notes: Wood-Boring Beetles in Homes.” ipm.ucanr.edu/home-and-landscape/wood-boring-beetles-in-homes/ (accessed 2026-11-10)
  22. Penn State Extension, “Carpenter Bees.” extension.psu.edu/carpenter-bees (accessed 2026-11-10)
  23. University of Kentucky Entomology, “ENTFACT-611: Carpenter Bees.” entomology.mgcafe.uky.edu/ef611 (accessed 2026-11-10)

Updated 2026-11-10. Built from sourced records. Spot an error? Tell us.