Guides

Termite Droppings: What Frass Actually Looks Like (And What It Isn't)

Termite droppings are 1 mm six-sided pellets that feel like coarse sand. How to identify them in 10 seconds, what they are not, and why a pile does not prove the infestation is still alive.

Published · How we source this

You are probably standing over a small pile of something with your phone in one hand. Here is the answer first.

The 10-second test

Run these three checks in order. You do not need a magnifying glass for any of them.

1. Are all the particles the same size? Drywood termite pellets are strikingly uniform and roughly 1 mm long. UF/IFAS measured them: a mean of 0.98 mm for Incisitermes minor and 0.87 mm for Cryptotermes brevis, each pellet weighing about 0.10 to 0.15 mg. Mississippi State describes them as relatively uniform in size. Sawdust is never uniform: one pile runs from dust to splinters. Nothing mechanical produces a heap of near-identical grains.

2. Roll a few between your fingers. Termite frass feels dry and gritty, like grains of coarse sand. If it smears away into your skin like face powder, it is powderpost beetle frass, which looks and feels like talcum powder. If it is fibrous and squashes rather than rolling, it is mechanical sawdust.

3. Is there anything else in the pile? Carpenter ant debris looks like pencil shavings and contains the remnants of ants and other insects the colony has been feeding on. Termite pellets are only pellets, nothing else.

If all three point to termites, you have drywood termites. What that pile does not tell you is whether the colony is still alive, and that turns out to be the hard part: see Is the infestation still active? below.

If you found no pellets but you did find mud tubes, or mud packed inside damaged wood, stop here and read No pellets, but mud tubes instead. That is the worse finding, not the better one, and there is a physiological reason those termites leave nothing on your floor.

What termite droppings actually look like

A drywood termite pellet is a hard, seed-like grain about 1 mm long. In cross-section it is a hexagon: six flattened or concave lengthwise surfaces separated by six ridges, with the ends rounded or domed. Texas A&M’s field guide puts it most usefully for anyone with a hand lens: six lengthwise ridges between depressed surfaces. Under about 10x magnification, what you actually see is six dark lines running the length of a pale seed.

You will not see those sides with the naked eye. Clemson is blunt about it: each pellet has six dented sides, but this can only be seen using a magnifying lens. A jeweller’s loupe or a phone macro lens will do it. At arm’s length, judge uniformity and grit instead, because those two properties are visible and they are diagnostic.

On size, the extension sources do not entirely agree, and it is worth knowing why. UF/IFAS reports measured means just under 1 mm, and Texas A&M gives 1/25 inch, which agrees. Clemson gives about 1/16 inch, roughly 60 percent larger. The UF figures are the ones derived from actual measurement of named species, so treat roughly 1 mm as the working number and expect some variation.

One popular comparison is worth discarding. Termite droppings are widely said to look like coffee grounds. They do not, on two counts: coffee grounds are irregular in size and shape, which is the opposite of the single most useful diagnostic, and documented pellet colours include cream and white. The extension sources’ own analogies are better and more precise: coarse sand, seed-like, or tiny stones.

Why the pellet has six sides

This is not trivia. It is the fact that explains everything else on this page, including why some termites leave a pile on your windowsill and the most destructive ones in the country cannot.

Drywood termites live inside dry wood with no contact with soil moisture. They have no water source except the wood they eat and the water they can recover from their own waste, so they reclaim it before excreting. The anatomy that does the squeezing has six parts. Zukowski and Su measured it directly: Cryptotermes brevis individuals re-absorb most of the water from consumed wood through the six thick rectal pads and produce six-sided fecal pellets (Insects 11(5):262, 2020). UF/IFAS states the same anatomy in plainer language: three pairs of rectal glands compress their feces to remove and retain all water possible before waste excretion. Three pairs is six.

Six pads, six sides. The hexagon is a moulding, not a coincidence.

The same paper measured the difference between termites that need this and termites that do not. Rectal pads in the drywood family run 160.5 to 171.6 micrometres wide, against 101.8 micrometres in the Formosan subterranean termite, which the authors note lives in moist underground galleries and does not have to re-absorb and/or conserve water within them to the same degree. Mississippi State gives the homeowner’s version: drywood termites must be very good at conserving moisture, and they are extremely stingy with the amount of water they lose with their feces.

That single chain answers the question most people are really asking. Pellets exist because the wood is dry. The wood is dry because there is no soil contact. So finding no pellets is not evidence that you have no termites. It may simply mean you have the other kind.

Is the infestation still active?

This is the real question, and almost every page you will find on this topic answers it wrongly by implication. A pile of frass is presented as proof of a live colony. It is not.

“It is not possible to determine, from fecal pellets alone, whether the infestation is currently active or how extensively the infestation extends throughout the wooden piece or structure.” Source: UC IPM, Drywood Termites

There are two reasons. Pellets are hard, dry and inert, so they persist indefinitely after a colony dies or is treated. And pellets stored inside galleries can be shaken loose long afterwards by ordinary building movement and vibration, arriving on your sill years late.

The sweep and recheck test

UC IPM publishes the one field test available, and hedges it in the same sentence:

“Cleaning up the fecal pellets around a kickout hole and checking a few days later to see if new pellets have appeared can help to determine if an infestation is active (as building vibrations and movement may also cause some pellets to appear).” Source: UC IPM, Drywood Termites

Do it anyway, because a negative result is worth having and it costs nothing. Sweep the pile completely, photograph the clean surface, write the date on a piece of tape next to it, and look again in a week. Fresh pellets are meaningful. No fresh pellets is not proof of anything.

If that feels unsatisfying, it is, and the research literature agrees with you rather than with the pest control blogs. Lewis and colleagues opened their study by stating the problem plainly: when fecal pellets appear after remedial treatment of a structure, it is difficult to determine whether this indicates that termites in the structure are still alive and active or not. Their approach was gas chromatography on the cuticular hydrocarbons in the pellets, tracking chemical change over 365 days (Journal of Chemical Ecology 36(11):1199-1206, 2010). That paper exists precisely because there is no reliable way to answer this by looking. UC IPM states where that leaves things: visual inspection by inspectors for evidence of termites and damage remain the mainstay of the industry.

Which is the honest answer to your question. The pile tells you drywood termites were there. Establishing whether they still are, and how far the galleries run, requires someone who can sound the wood, open the right places and read the structure. That is what a licensed inspection is for.

Five things this pile could be

The comparison most sites publish is termites versus sawdust versus rodent droppings. Rodent droppings are the least useful of those: mouse droppings are 1/8 to 1/2 inch long and pointed at both ends, roughly ten times the size of a termite pellet, and nobody confuses them at arm’s length. The comparison that actually catches people out is powderpost beetles, and it is missing from essentially every page on this subject.

Drywood termite frassPowderpost beetle frassCarpenter ant frassMechanical sawdustMouse droppings
Particle formUniform six-sided pellets with lengthwise ridges, seed-likeFine powder, no visible particle structureCoarse fibres like pencil shavingsIrregular splinters and fibresCylindrical, pointed at both ends
SizeAbout 0.87 to 1.0 mm, highly uniformTalc-fine to meal-likeMillimetres to centimetresDust to chips in one pile1/8 to 1/2 inch
In the fingersDry and gritty, like coarse sandLyctid: like talcum powder. Anobiid: powdery but gritty. Bostrichid: meal-like, stays packedFibrousFibrous, compressibleFirm
Insect parts in it?NoNoYes, the giveawayNoNo
Associated holeKick-out hole 1 to 2 mm, usually pluggedRound exit holes, open, 1/32 to 1/4 inchSlit-like openings, no round holeSaw or drill marksNone
GalleryPacked with pelletsPacked with powder, surface blisteredClean, almost sandpaperedn/an/a

Sources for the table: NC State on carpenter ants, which describes carpenter ant frass as pencil-shaving-like with insect body parts included and their galleries as looking almost sandpapered, and which also gives all three wood-insect gallery states in one place; NC State on powderpost beetles for lyctid and anobiid frass texture; University of Kentucky EF-616 for exit hole sizes by beetle family and the meal-like bostrichid powder; University of Kentucky EF-617 for mouse droppings; and UF/IFAS EENY-248 for termite pellet dimensions and texture.

Why powderpost beetles are the confusion that matters

Small pale particles, in a pile, under wood, coming out of a small round hole. That describes both problems, and it is the reason a homeowner gets this wrong. The separation is clean once you know it:

  • Termite pellets are discrete objects. You can see individual grains. They roll. Smear one and it does not disappear.
  • Lyctid powderpost frass is a powder. It looks and feels like talcum powder and vanishes into your skin when you rub it.
  • The holes behave differently. Powderpost exit holes are round, open and stay open, 1/32 to 1/4 inch depending on the family. Drywood kick-out holes are 1 to 2 mm and normally sealed shut.

There is one useful asymmetry here. The powderpost beetle literature does contain a freshness test that the termite literature lacks: active infestations usually have powder the colour of freshly sawn wood streaming from or accumulating near exit holes, while old frass is yellowed and caked, or covered with dust, webbing or debris. Do not transfer that test to termite pellets. It does not work there, for the reasons in the section above.

The fastest route to an answer

In order of how quickly each check resolves:

  1. Insect body parts in the debris? Carpenter ants. This is the only fully positive tell in the set.
  2. Does it smear into powder, or roll as grains? Powder means beetles. Grains mean termites.
  3. Is every particle the same size and shape? Uniform means biological, so termite. Varied means mechanical.
  4. Under a lens, six ridges running lengthwise? Drywood termite, confirmed.
  5. No pellets at all, but mud tubes or mud packed into damaged wood? Subterranean termites. Read on.

No pellets, but mud tubes instead

Subterranean termites do not produce droppings you will ever find in a pile. This is commonly explained as their droppings being “less noticeable” or hidden inside walls. That is the wrong mechanism and it sends people hunting for something that does not exist.

They never form pellets at all. Their faeces stays liquid and pasty, and the colony uses it as building material. It ends up in three places:

The damage pattern differs too, and it is worth checking if you have suspect wood. Subterranean galleries are hollow, enclosed, more or less longitudinal cavities that follow the grain, attacking the softer springwood and leaving the harder summerwood standing. Drywood galleries by contrast are clean and free of debris, and the tunnels can run across the grain, with pellets stored in chambers off to the side.

Formosan termites: the faeces is in the wall

The Formosan subterranean termite is also a subterranean termite, so no pellets. Its distinguishing product is the carton nest, which is a blend of soil, wood pulp, termite saliva, and termite feces packed into structural voids and hollowed tree centres. With a mature Formosan infestation there may be kilos of termite faeces in the building. It has been built into a wall cavity as a nest rather than swept into a pile on your floor. Mississippi State lists mud shelter tubes on the upper portions of a structure as a Formosan-specific indicator, because once a carton nest holds its own moisture the colony no longer needs soil contact.

Dampwood termites

Dampwood termites do produce pellets, but different ones, and they usually stay put. UC IPM describes them as rounded at both ends, football shaped and elongated, but lacking the clear longitudinal ridges common to drywood termite pellets. Because the wood is wet, the pellets clump: UF/IFAS notes that evidence of dampwood termites is a mix of clumped and loose fecal pellets, typically inside the galleries rather than in a clean pile below. The absent ridges are the separator.

Why you cannot find the hole

A common and frustrating experience: the pellets are obviously there, and there is no hole anywhere above them.

The hole is there. It is usually 1 to 2 mm in diameter, and it is closed. UF/IFAS: these holes are extremely small and usually are sealed with a plug of wet feces and pellets when not in use. The termites open it, push out the accumulated pellets, and seal it again. UF’s advice on locating one is to carefully search wood surfaces directly above where fecal pellets accumulate.

What the shape of the pile tells you

This is the most useful thing on this page for actually finding the source, and it comes straight out of the extension literature. Pellets accumulate in piles or scatter circles depending on the height of the hole from the ground, and the diameter of the frass piles is proportional to the height of the kick-out holes.

So:

  • A tight cone means the kick-out hole is close above it. Search that patch of wood carefully.
  • A wide, thin scatter means the hole is high up: a ceiling, an upper beam, the top of a door frame. Mississippi State describes exactly this: from a low hole the pellets form a neat little, attention-getting pile, while from higher up the falling pellets bounce and scatter, making them easy to mistake for dust or debris.

Look at window sills and their tracks, door frames and thresholds, skirting and trim, attic framing, exposed beams, sub-floor timbers, and the tops of built-in furniture. Mississippi State’s point about the scatter is worth taking seriously: from a distance these fecal pellets look like dust or debris and are often not recognised as a sign of an active termite infestation. If you have been sweeping something off a sill for months, that may have been this.

Colour tells you nothing

Pellets are documented in cream, red or black, and Clemson describes piles with a salt-and-pepper look where black, cream coloured or a combination of pellets sit together.

You will read almost everywhere that the colour tells you which wood the termites are eating. The best available source says that is not true, and says so explicitly:

“…can be a variety of colors, including cream, red, or black… It is unknown what determines pellet color, as color is unaffected by temporal changes or the color of the wood the termites are feeding on.” Source: Gordon, Scheffrahn and Su, UF/IFAS EENY-79

In fairness, this is contested inside the extension literature itself. A UC IPM photo caption states the opposite: “The color can vary depending on the wood species fed on.” Both are university extension sources and they contradict each other directly. The asymmetry is worth noting: the UF statement is a substantive claim in the body of an extension publication written by the taxonomists who described these species, and the UC IPM statement is a caption on a photograph.

The practical conclusion is the same whichever way that disagreement eventually resolves. Do not use colour to identify anything. Not the wood, not the termite species, not the age of the pile. Colour is the most visually obvious property of a termite pellet and the least diagnostic one. Shape, uniformity of size, and grit are what carry information.

What frass does not tell you

How long they have been there, except that it is probably a while. A drywood colony is slow to become visible. UF/IFAS on Incisitermes minor: it may take five to seven years before an incipient colony produces visible feeding damage or is found infesting wood, and for Cryptotermes species it may take years for damage to be detected. Frass is not an early warning. It is a late one. That is a reason to move promptly, not to panic.

Which drywood species it is. Pellets identify the family reliably. They do not identify the species. UF/IFAS did measure a species-level difference, 0.98 mm for I. minor against 0.87 mm for C. brevis, but a 0.11 mm difference is a laboratory measurement, not a homeowner test.

How far the infestation extends. UC IPM says this in the same sentence as the activity point: you cannot determine from pellets alone how extensively the infestation extends throughout the wooden piece or structure.

Whether it is dangerous to have around. Not in the way it is usually framed. This is not a pathogen problem. There is, however, a plausible allergen question that is worth stating accurately rather than dismissing. Researchers found that Formosan termite proteins share more than 60 percent similarity with German and American cockroach allergens, with a tropomyosin homolog above 80 percent, and wrote that dwellings with active dry wood termite infestations accumulate frass (termite droppings) which likely contain potential allergens (PLoS One 12(8):e0182260, 2017). The same authors flag that real-world exposure may be limited. So: not established as a clinical hazard, but “completely harmless” overstates what is known. Sweep it up rather than vacuuming it into the air, and do not let anyone tell you either that it is dangerous or that the question is settled.

What to do next

  1. Collect a sample. A clear zip bag against white paper photographs well and gives an inspector something to identify directly.
  2. Photograph it in place, with a coin in the frame for scale. Note where it was and the date.
  3. Sweep the area completely and mark the date next to it. Check in a week. New pellets are informative; no new pellets is not, for the reasons above.
  4. Look directly above the pile if it was a tight cone, and high up if it was a wide scatter.
  5. Do not open up or treat the wood yourself before it has been inspected. Both the extent of the galleries and the choice of treatment depend on what an inspector finds, and disturbed evidence makes that harder.

The honest position is the one UC IPM takes: pellets prove drywood termites were present, and visual inspection by a professional is still how the extent and the activity get established. If the pellets check out, the next step is a licensed wood-destroying-organism inspection, by someone whose licence you can actually verify.

That is what this site is for. We list inspectors by state and metro with their licence number, issuing board, licence status and the date we last verified it, so you can check the person before you call them. If you are in California, start with termite inspectors in Los Angeles. In Texas, start with Houston. Otherwise, pick your state from the full list of licensed termite inspectors.

Sources

Every claim on this page is linked inline to one of the following. No pest control company page is cited as a source of fact anywhere in this article.

University extension

Peer-reviewed