Signs of Termites: How to Tell If You Have Termites (2026)

Last updated: March 2, 2026

By James — 25-year pest control industry veteran

Knowing the signs of termites early can save thousands of dollars in structural repairs. Termites cause an estimated $5 billion in property damage across the United States each year, and most homeowners insurance policies do not cover termite damage. This guide walks through the warning signs of a termite infestation, how to inspect your home, and when to call a professional for termite treatment.

8 Warning Signs of Termites

Termites are often called "silent destroyers" because they can feed on wood for years before homeowners notice any evidence. These are the most common signs that termites are present in or around your home.

1. Mud tubes on foundation walls

Subterranean termites build pencil-width mud tubes along foundation walls, basement walls, and crawl space piers. These tubes are made of soil, wood particles, and saliva, and they provide moisture and protection as termites travel between the soil and your home's wood. Mud tubes are the single most reliable indicator of a subterranean termite infestation.

To test a mud tube, break off a small section and check back in a few days. If the tube is repaired, termites are actively using it. Even if it is not repaired, termites may still be present elsewhere in the structure.

2. Frass (termite droppings)

Drywood termites push their droppings out of small holes near their tunnels. These droppings, called frass, look like tiny wood-colored pellets or sawdust. You may find small piles of frass on windowsills, along baseboards, or beneath wooden furniture. Frass pellets are about 1 millimeter long with six concave sides and rounded ends.

Frass is specific to drywood termites. Subterranean termites use their droppings to build mud tubes rather than pushing them out.

3. Hollow-sounding wood

Termites eat wood from the inside out, leaving a thin outer shell intact. Tap on wood surfaces with a screwdriver handle or knuckle. Damaged wood will sound hollow or papery compared to solid wood. In advanced cases, you can push a screwdriver straight through what appears to be a solid beam or baseboard.

4. Discarded wings

Termite swarmers (also called alates) shed their wings after mating and finding a new nesting site. You may find piles of small, translucent wings near windows, doors, light fixtures, or other entry points. All four wings are roughly the same size, which distinguishes termite swarmers from flying ants, whose front wings are larger than the back pair.

5. Swarmers (flying termites)

Seeing flying termites inside your home, especially in spring or after rain, is a strong indication of a nearby colony. Swarmers are drawn to light and are often found near windows and doors. A swarm inside the home means a mature colony is likely living in or immediately adjacent to the structure.

6. Sagging floors and ceilings

Advanced termite damage weakens structural supports, causing floors to sag, buckle, or feel spongy underfoot. Ceilings may droop or develop visible damage. By the time structural sagging occurs, the damage is typically extensive and expensive to repair.

7. Tight-fitting doors and windows

Termites produce moisture as they eat through wood, causing frames to swell. If doors or windows that previously opened easily are suddenly difficult to open or close, termite damage to the surrounding frame may be the cause. This is often mistaken for seasonal humidity changes.

8. Bubbling or peeling paint

Moisture from termite activity behind walls can cause paint to bubble, peel, or blister. This looks similar to water damage. If there is no plumbing or roof leak to explain the paint damage, termites may be the hidden cause.

Signs by Termite Type

The three main types of termites in the United States leave different evidence. Knowing which type you are dealing with helps determine the right treatment approach.

Subterranean termites

Subterranean termites are the most common and destructive type in the United States. They live in soil and build mud tubes to access wood above ground. Look for mud tubes on foundation walls, basement walls, and support piers. Subterranean termites cause the majority of termite damage nationwide and are found in every state except Alaska.

Drywood termites

Drywood termites live entirely inside the wood they consume, with no soil contact. They are most common in southern and coastal states. The primary evidence is frass (tiny pellets pushed out of the wood) and discarded wings. Drywood termites can infest attic rafters, furniture, and framing that is not connected to the ground.

Dampwood termites

Dampwood termites require high moisture and are typically found in decaying wood, logs, and stumps. They rarely infest homes unless there is a moisture problem such as a leak or poor drainage. Fixing the moisture source often eliminates dampwood termites without additional treatment.

Where to Inspect Your Home

A thorough DIY inspection covers both the interior and exterior of your home. Focus on areas where wood meets soil or moisture.

Exterior inspection

• Foundation walls: Look for mud tubes from the soil line upward. Check the entire perimeter.
• Where wood contacts soil: Deck posts, fence posts, porch supports, and siding that touches the ground are high-risk areas.
• Mulch and landscaping: Wood mulch within 6 inches of the foundation attracts termites. Check for mud tubes leading from mulch beds to the house.
• Exterior woodwork: Probe window frames, door frames, and trim boards with a screwdriver. Damaged wood will feel soft or crumble.
• Gutters and downspouts: Clogged gutters create moisture near the foundation, which attracts subterranean termites.

Interior inspection

• Basement and crawl space: The highest-risk areas. Check all wood beams, joists, sill plates, and support posts for mud tubes and damage.
• Behind walls: Tap along baseboards and drywall with a screwdriver handle. Listen for hollow sounds.
• Attic: Inspect exposed rafters and sheathing for drywood termite frass or damage.
• Bathrooms and kitchen: Check under sinks and around plumbing penetrations where moisture may attract termites.
• Garage: Inspect wood framing, especially where the garage meets the foundation.

How Fast Do Termites Cause Damage?

Termite damage develops gradually but compounds over time. A single subterranean termite colony can contain 60,000 to over 1 million workers. At that size, a colony can consume roughly one foot of a 2x4 board per year.

These are estimates for untreated infestations with a mature colony. The key takeaway is that early detection and treatment dramatically reduce repair costs. A $1,200 to $3,500 termite treatment today can prevent tens of thousands in future repairs.

DIY Inspection Tips

You can perform a basic termite inspection yourself with a few simple tools. While not a substitute for a professional inspection, a DIY check helps identify obvious signs.

• Flashlight: Essential for inspecting dark areas like crawl spaces, basements, and behind stored items.
• Flathead screwdriver: Use to probe wood for softness and tap for hollow sounds. Push the tip into suspected damage areas.
• Moisture meter: Available for $20 to $40 at hardware stores. Termite-damaged areas often have elevated moisture readings even when there is no visible water source.
• Inspect annually: Walk the perimeter and check the basement or crawl space at least once a year, ideally in spring when swarmers are most active.
• Keep records: Note any suspicious signs and photograph them. This helps a professional assess the situation if you call for an inspection later.

When to Call a Professional

Call a pest control professional immediately if you notice any of these signs:

• Mud tubes on your foundation or basement walls
• Flying termites or discarded wings inside your home
• Frass (termite droppings) near wood surfaces
• Hollow-sounding wood when tapped
• Visible damage to wood beams, baseboards, or framing
• Sagging floors or ceilings

Professional termite treatment costs $1,200 to $3,500 depending on the treatment method and severity of the infestation. Our termite treatment cost guide breaks down pricing by method, including liquid barriers, bait stations, and fumigation.

For a comprehensive overview of all pest control costs, see our pest control cost guide.

Frequently Asked Questions