Termite Droppings and Damage: How to Identify Them

Termites do their damage out of sight, so the clues they leave behind are how most people first catch them. The two biggest are droppings and damaged wood — and knowing what each looks like tells you a lot before an inspector ever arrives.

What termite droppings (frass) look like

Drywood termites keep their galleries clean by pushing waste out through small “kick-out” holes, leaving little piles of pellets called frass. The pellets are tiny, uniform and six-sided, ranging from tan to dark brown depending on the wood, and they look like coarse sand or ground pepper. You'll usually find a small mound on a window sill, a baseboard, the garage floor, or any flat surface directly below infested wood.

Frass vs. sawdust — how to tell them apart

This is the question I get most. Termite frass is remarkably uniform — every pellet roughly the same size and shape, with six flattened sides. Sawdust, and the shavings carpenter ants or wood-boring beetles leave, are irregular, stringy and often mixed with bits of insect or debris. If the “sawdust” is a neat pile of identical little pellets, it's almost certainly drywood termite frass.

Mud tubes — the subterranean sign

Subterranean termites don't leave frass — they reuse it inside their tunnels. Instead, their tell is the mud tube: a pencil-width tube of soil and saliva running up a foundation, pier or garage wall, built to keep the termites moist as they travel from the soil to the wood. A mud tube means subterranean termites, which are treated with a Termidor barrier rather than the spot or tent methods used on drywood.

What termite damage looks like

Termites eat wood from the inside out, so the surface can look fine while the inside is hollowed into galleries. Watch for wood that sounds hollow or papery when tapped, paint or veneer that ripples and blisters as if there's moisture underneath, sagging or spongy floors, and doors or windows that suddenly stick. Because so much of the damage is internal, visible signs usually mean activity has been going on for a while.

What to do if you find these signs

Don't clean it all up just yet. Collect a small sample of the pellets or take a photo, note exactly where you found it, and avoid spraying the area — those details help pin down the type and location. Then get an inspection. Identifying drywood vs. subterranean is what determines the fix: localized drywood often calls for spot treatment, subterranean for a Termidor barrier. Ask for a free quote if you've spotted any of these.