Termites on wood are surprisingly hard to spot because most of them never come to the surface. The workers that actually eat wood are completely white, eyeless, and only about a quarter-inch long. What you’re far more likely to see are the signs they leave behind: pencil-width mud tubes running along a foundation, tiny sand-colored pellets collecting beneath a board, or wood that sounds hollow when you tap it. Knowing what both the insects and their damage look like helps you catch an infestation before it becomes serious.
What Termites Actually Look Like
A termite colony has several castes, and each looks different. Worker termites, the ones doing the damage inside your wood, are completely white, soft-bodied, and lack eyes entirely. They have a straight, tube-shaped body with no pinched waist, which is one of the easiest ways to tell them apart from ants. Workers are small, roughly 1/8 to 1/4 inch long, and you’ll almost never see them unless you break open an infested piece of wood.
Soldier termites are slightly more distinctive. They have enlarged, darker-colored heads with heavy mandibles (jaw-like pincers) that they use to defend the colony. Their bodies are still pale, but that oversized brown or orange head makes them easy to identify.
The termites you’re most likely to encounter in the open are swarmers, the winged reproductive adults that leave the colony to start new ones. Swarmers are darker, ranging from yellowish-brown to nearly black depending on species, and measure about 1/2 inch long including their wings. Their wings are a key identifier: both pairs are the same length and shape, and they shed them quickly after landing. If you find a pile of identical, translucent wings on a windowsill or near a light source, that’s a strong sign of a termite swarm.
How to Tell Termites From Carpenter Ants
Carpenter ants and termites both damage wood, and their swarmers look similar at first glance. Three quick visual checks will sort them out:
- Body shape: Termites have a broad, straight waist with a uniform tube-like body. Ants have a distinctly narrow, pinched waist between their thorax and abdomen.
- Antennae: Termite antennae are straight and look like a string of tiny beads. Ant antennae have a sharp elbow bend in the middle.
- Wings: Termite swarmers have two pairs of wings that are all the same size. Ant swarmers have larger front wings and smaller hind wings.
Color can also help. Ants are typically black or deep red and opaque. Termites range from creamy white (workers) to tan or brown (swarmers), and some can appear slightly translucent.
Mud Tubes on Wood and Foundations
Subterranean termites, the most common type in the United States, build mud tubes to travel between their underground colony and the wood they’re feeding on. These tubes are made from a mixture of soil, wood fibers, saliva, and feces, and they’re earth-colored, usually tan or brown. They’re roughly the width of a pencil, though they can range from 1/4 inch to 1 inch in diameter.
You’ll find them running vertically along foundation walls, piers, or any surface that connects the ground to wood. Some tubes branch out in multiple directions as termites explore for new food sources. These exploratory tubes tend to be thin and fragile. Working tubes, the ones actively carrying termites back and forth, are sturdier and more organized. Occasionally you’ll see “drop tubes” hanging down from overhead wood like tiny stalactites. These are lighter in color because they contain more wood fiber and less soil.
If you find a mud tube, break off a small section and check back in a few days. If the tube has been rebuilt, the infestation is active.
What Termite Damage Looks Like on Wood
The type of damage you see depends on which termite species is responsible.
Subterranean Termite Damage
Subterranean termites prefer to eat the softer springwood grain while leaving the harder summerwood layers intact. This creates a layered, almost honeycomb pattern inside the wood, with alternating strips of damaged and undamaged material. Their galleries (internal tunnels) often contain traces of soil. On the surface, damage from subterranean termites can make wood floors look like they have water damage, with blistering or swelling that indicates feeding just below the surface.
Drywood Termite Damage
Drywood termites eat both the soft and hard layers of wood, carving out smooth, sculptured galleries that look almost polished inside. Because they live entirely within the wood with no connection to soil, their tunnels are clean except for fecal pellets. They consume wood from the inside out, often leaving just a paper-thin shell of wood or paint on the outside. When you tap infested wood, it sounds distinctly hollow. In severe cases, you may see actual holes breaking through the surface.
Frass: The Pellets Near Infested Wood
Drywood termites push their waste out of tiny “kick holes,” about 1/16 inch in diameter, drilled through the wood surface. The fecal pellets that accumulate below are one of the most reliable signs of a drywood infestation. Each pellet is roughly 1/32 inch long, and from a normal viewing distance they look like fine dust, sand, or sawdust collecting on a floor or shelf beneath the infested wood.
Under magnification, the pellets are unmistakable. They have a distinct six-sided shape, blunt at one end and pointed at the other, with long grooves running down each surface. Their color matches the wood the termites are eating, so they can range from light tan to dark brown. No other wood-destroying insect produces pellets with this shape. Carpenter ant frass, by comparison, is a messier mix of wood shavings and dead insect parts.
If you suspect drywood termites, try tapping gently on the wood near where you found the pellets. This can dislodge more pellets from the kick holes and confirm the location of the infestation.
Surface Signs You Can Spot Early
Because termites work inside wood rather than on its surface, visible damage often means the infestation has been active for a while. Still, several surface clues can tip you off earlier:
- Blistering or buckling paint: This can indicate termites feeding just beneath the surface, especially on baseboards, door frames, and window trim.
- Hollow-sounding wood: Knock on exposed wood with your knuckle. Solid wood produces a firm thud; termite-damaged wood sounds papery or hollow.
- Visible galleries: Long, slim carved lines or ridges on wood surfaces, particularly on structures close to the ground like baseboards or floor joists.
- Doors and windows that stick: Termite damage can warp frames enough to make them difficult to open or close, which is easily mistaken for humidity or settling.
- Discarded wings: Piles of small, uniform wings near windowsills, light fixtures, or doorways indicate a recent swarm from a nearby colony.
The areas most worth checking are wherever wood contacts or sits near the ground: foundation sills, porch supports, deck posts, and exterior trim boards. For subterranean termites, look for mud tubes first. For drywood termites, look for pellet piles and kick holes in exposed wood, especially along fascia boards and eaves.