Houston is one of the highest-risk cities in the United States for termite damage. The combination of extreme humidity, warm temperatures that persist nearly year-round, and the presence of two of the most destructive termite species in North America — the Eastern subterranean termite and the Formosan subterranean termite — puts every Houston home at risk. The USDA estimates that termites cause $5 billion in property damage nationally each year, and Houston homeowners bear a disproportionate share of that cost.
Formosan vs. Subterranean Termites in Houston
Understanding which species you're dealing with matters because the two behave differently and require different treatment approaches. Eastern subterranean termites are the most widespread species in North America — they're found throughout Houston and are a serious pest, but their colonies tend to be smaller (a few hundred thousand workers) and they damage wood more slowly.
Formosan subterranean termites are in a different league entirely. Introduced to the Gulf Coast through infested lumber and military shipping crates after World War II, Formosans have established a firm presence in Houston and surrounding counties. A mature Formosan colony can contain 3 to 10 million workers and consume approximately 13 ounces of wood per day — roughly 1,000 times faster than an Eastern subterranean colony. They can also build moisture-retaining carton nests inside walls, allowing them to survive without ground contact. Both species swarm in Houston; Formosans typically swarm on warm, humid evenings from April through June.
10 Signs of Termite Damage to Watch For
1. Mud Tubes on Foundation Walls
Mud tubes (also called shelter tubes) are pencil-width tunnels made of soil, wood particles, and termite saliva that subterranean termites build to travel between their underground colony and the wood they're consuming. You'll most commonly find them running up concrete foundations, along pipes, inside crawl spaces, or in garage walls. Break open a tube — if it's active, termites will be visible inside. An abandoned tube will be dry and empty, though that doesn't mean the infestation is gone.
2. Hollow-Sounding Wood
Termites eat wood from the inside out, consuming the soft grain while leaving a thin outer shell intact. Tap on baseboards, door frames, and wood paneling with your knuckle or a screwdriver handle. A hollow or papery sound instead of a solid thud is a strong indicator of termite activity within. Wood that collapses when prodded with a screwdriver has almost certainly been hollowed by termites.
3. Frass (Termite Droppings)
Drywood termites (less common in Houston than subterranean species but present) push their fecal pellets out of small kick-out holes in the wood they're infesting. The frass looks like tiny sand granules or sawdust and accumulates in small piles on surfaces below the infested wood. Subterranean termites use their frass to construct their mud tunnels, so loose frass piles are more indicative of drywood termites.
4. Swarmers or Discarded Wings
Termite swarmers are reproductive termites that emerge in large numbers to start new colonies. In Houston, you may see them clustering around windows, light fixtures, or door frames — they're strongly attracted to light. Swarmers shed their wings immediately after mating, so small piles of translucent wings near windowsills, doorways, or vents are a reliable sign that a swarming event occurred in or near your home. Many homeowners mistake termite swarmers for flying ants — termites have straight antennae, equal-length wings, and a uniform waist, while ants have bent antennae, unequal wings, and a pinched waist.
5. Buckling or Bubbling Paint
Subterranean termites introduce moisture as they work through wall studs and framing members. This moisture causes paint to bubble, peel, or develop a water-damaged appearance even in areas that have never experienced a plumbing leak. Similarly, wallboard that feels soft or spongy when pressed could indicate termite activity behind it.
6. Tight-Fitting Doors and Windows
As termites damage wooden door and window frames, they produce moisture that causes the wood to warp. Doors or windows that suddenly become difficult to open or close — especially in the absence of recent rain or humidity changes — may be reacting to structural changes caused by termite activity in the surrounding frame.
7. Visible Termite Tunnels in Wood
If you break open a piece of damaged wood or look at a cross-section of a board, you may see the maze-like gallery patterns termites carve as they eat. These galleries run with the grain of the wood and are lined with mud in subterranean species.
8. Sagging Floors or Ceilings
In severe infestations, floor joists, subfloor panels, or ceiling joists become so compromised that floors feel spongy underfoot or ceilings develop visible sag. This level of damage typically represents years of infestation and very significant structural repair costs — often $10,000 to $50,000 or more.
9. Clicking Sounds in Walls
Soldier termites bang their heads against the walls of tunnels to signal danger to the colony. In a heavy infestation, you may actually be able to hear a faint clicking or rustling sound if you press your ear to an infested wall. It's a subtle sound, but unmistakable once you know what to listen for.
10. Your Neighbor Has Termites
Subterranean termite colonies extend underground through interconnected tunnel networks that can span an entire city block. If a neighbor has been treated for termites, your property is at elevated risk, particularly if you share a fence line, have adjacent landscaping, or live in an older neighborhood with significant wood-to-soil contact.
Pro Tip
Important: Termite damage is almost never covered by standard homeowner's insurance policies. Insurers classify it as a preventable pest issue, not a sudden and accidental loss. A termite protection plan with regular inspections is the only financial backstop available to Houston homeowners.
What to Do If You Find Signs of Termites
- Do not disturb the mud tubes or affected areas — disrupting an active colony can cause it to scatter and make treatment more difficult
- Document what you found with photos, noting the location and approximate size
- Contact a licensed pest control company for a professional termite inspection — many offer free inspections
- Ask specifically about Formosan termite experience, as they require different treatment approaches
- Get the inspection report in writing, along with treatment recommendations and a repair cost estimate if applicable
- If purchasing a home in Houston, always insist on a WDI (Wood-Destroying Insect) report from a licensed inspector
The Cost of Ignoring Termite Warning Signs
Termite colonies grow exponentially. A small, newly established colony that might cost $500–$1,500 to treat can grow into a massive infestation requiring $3,000–$8,000 in professional treatment plus tens of thousands in structural repairs if left unchecked for a few years. In Houston's warm climate, colonies can grow year-round with no winter slowdown. Early detection and prompt treatment are always far less expensive than dealing with advanced damage.