7 Signs of Termite Damage Most Homeowners Miss

Termites cause about five billion dollars in damage to U.S. homes every year, and almost none of that damage is covered by homeowners insurance. The reason the number is so high isn't that termites are especially fast — a mature colony eats roughly a pound of wood a week, which is slow. It's that they eat in secret. A colony can live inside your subfloor for five or six years before anyone notices, and by then the repair bill is measured in tens of thousands of dollars.

Here are the seven signs our inspectors look for first, in the order we usually find them.

1. Mud tubes on the foundation

Subterranean termites — the species responsible for most damage in the U.S. — build pencil-thin tunnels of mud and saliva to travel between soil and wood without drying out. Look on the outside of your foundation, on interior basement walls, and on the piers under a crawlspace. Even an abandoned tube is evidence that a colony was working the structure recently.

2. Discarded wings near windowsills

Every spring, reproductive termites (called swarmers or alates) fly out of mature colonies to start new ones. They lose their wings almost immediately and the wings pile up on windowsills, in spider webs, and around light fixtures. Four wings of equal length in a small pile is termites; unequal wings are usually flying ants.

3. Floors that flex or sag

A hardwood or laminate floor that suddenly feels 'bouncy' in one spot often means the subfloor underneath has been hollowed out. The finish layer holds up fine because it's only supporting your weight in shear — the joists doing the real work are gone.

4. Paint that blisters or bubbles

Drywood termite galleries run just under the painted surface of trim, baseboards, and door frames. As they eat, moisture from the wood pushes the paint outward in small bubbles that look like a water leak. Press on the bubble — if it crunches, that's frass and gallery, not moisture.

5. Tight-fitting doors and windows

Termite damage in a frame changes the frame's shape by a few millimeters, which is enough to make a door stick or a window refuse to slide. Homeowners usually blame humidity and shave the door down. A year later it sticks again.

6. Piles of what looks like sawdust or coffee grounds

Drywood termites push their droppings — called frass — out of small kick-out holes in the wood. It looks like fine, uniform pellets of coffee grounds or coarse sand. If you sweep it up and it comes back within a week, you have an active colony directly above the pile.

7. A hollow sound in structural wood

Tap along baseboards, door frames, window sills, and any exposed beams with the handle of a screwdriver. Solid wood makes a dull thud; hollowed wood sounds papery, almost like tapping on a cardboard box. Pay special attention to wood within a foot of the ground and anywhere plumbing enters the house.

What to do if you find any of the seven

Don't spray it, don't disturb it, and don't rip anything apart to 'see how bad it is.' Termites respond to disturbance by relocating within the same structure, which turns a treatable local infestation into a scattered one. Take clear photos, note the location, and get a professional inspection scheduled within the week. A licensed technician can identify the species (subterranean, drywood, or Formosan — treatment differs for each), map the extent, and recommend either a liquid termiticide barrier, a baiting system, or targeted spot treatment.

Every home in a termite-active region should get a professional inspection once a year, and every home should get one before a purchase or sale. The inspection costs less than a night out; the damage from skipping it can rewrite your retirement plan.