Termites in the Walls — How to Find Where They're Coming From

1 day ago

8 min read

Termites are infuriating precisely because they work out of sight. By the time anything shows on the surface, they’ve often been feeding inside your walls for months — quietly hollowing out studs and framing while the paint looks perfectly fine from your side. Maybe you tapped a wall and it sounded oddly hollow, or you noticed the paint bubbling near a window, or a neighbor just got tented and now you’re eyeing every baseboard with suspicion. Whatever brought you here, you want to know what’s really going on behind the drywall.

The good news is that even though termites hide, they leave tells. Learning how to find termites in walls is mostly about knowing which subtle signs to look and listen for — and understanding where a flashlight and a screwdriver stop being enough. Let’s go through the signs, the simple checks you can do yourself, and the tools professionals use to confirm what’s happening inside a wall without ripping it open.

Quick Answer

What are the signs of termites in walls? Hollow-sounding wood, blistered or bubbling paint, tiny pinholes with frass beneath, mud tubes, faint sagging, and swarmers near windows.

Can I check myself? Yes — tap and listen for hollowness, gently probe suspect wood, and inspect baseboards and window frames with a flashlight at an angle.

Can termites be in a wall with no visible sign? Yes. Early activity is often invisible, which is why a hollow sound or a swarmer can be the only clue.

How do pros find them? FLIR thermal imaging, moisture meters, and acoustic detection reveal activity behind drywall without opening it.

What should I do if I suspect it? Don’t start cutting walls — get an inspection. Call Termike at (888) 683-3592.

Why You Can Trust Termike Pest Control

License: California Structural Pest Control Board — License PR8832 (Branch 2 & 3 certified)

Membership: National Pest Management Association (NPMA)

Experience: 25+ years serving Orange County, LA County, Riverside & San Bernardino County

See Inside Walls Without Opening Them: We use FLIR thermal imaging, moisture meters, and acoustic detection to locate activity behind drywall — no guesswork, no unnecessary holes

Honest Findings: If the signs turn out to be something other than termites, we’ll tell you — we’re here to diagnose, not to upsell

The Signs That Reveal Termites in Walls

Termites inside a wall give themselves away in small ways long before the wall fails. The trick is knowing these subtle signals are worth taking seriously instead of writing them off as normal house quirks.

What You Can See and Hear

Most of the earliest clues are visual or audible if you know what you’re looking for. Blistered, bubbling, or uneven paint can signal termites or moisture just beneath the surface. Tiny pinholes in drywall with a sprinkle of what looks like sawdust or coffee grounds below them are drywood termite frass being kicked out of the wood. Faint mud tubes emerging from baseboards or outlets point to subterranean termites. A section of wall or trim that sounds hollow or papery when tapped often means the wood behind it has been eaten out. And a soft clicking or faint rustling inside a quiet wall can be the termites themselves. Termike’s guide on the warning signs of termites and the one on whether you can hear termites expand on these tells.

The University of California Integrated Pest Management Program lists discarded wings, pellet-like frass, mud tubes, and damaged or hollow-sounding wood among the primary indicators of termite activity — the same cues that show up on and inside walls.

How to Find Termites in Walls Yourself

You can do a surprising amount of initial detective work without any special equipment. The approach to how to find termites in walls on your own is methodical observation — moving along the wall and checking each type of sign deliberately rather than glancing around and hoping something jumps out.

Simple Checks for How to Find Termites in Walls

When you’re working out how to find termites in walls with just household tools, a few techniques do most of the work. Tap along the wall, baseboards, window frames, and door frames with the handle of a screwdriver and listen for a hollow or papery change in tone. Shine a flashlight across the surface at a low angle — raking light reveals blistering, ripples, and pinholes that straight-on light hides. Gently press suspect wood with a screwdriver tip; wood that crumbles or gives way easily may be hollowed out (press, don’t gouge — you’re testing, not demolishing). Check the floor along baseboards for frass piles, and inspect around windows, where termite swarmers inside the house and their discarded wings often collect. Work room by room so you don’t miss a wall.

Why Professionals Find What You Can’t

Here’s the honest limit of DIY detection — your eyes and ears can only catch termites that have left a surface clue, and plenty of active infestations haven’t yet. This is where professional tools change the game by seeing straight through the drywall.

1. FLIR thermal imaging. Termite activity and the moisture that comes with it create temperature differences a thermal camera detects behind intact walls. Termike’s guide on how thermal imaging detects termites explains the science

2. Moisture meters. Subterranean termites bring moisture into the wood they infest. A moisture meter flags abnormally damp spots inside a wall that signal a problem

3. Acoustic detection. Specialized equipment can pick up the sound of termites feeding inside framing, confirming activity you could never hear unaided

4. Trained probing and experience. A professional knows exactly where termites concentrate — near plumbing penetrations, window frames, and sill plates — and how to confirm it. Termike’s guide on detecting termites behind walls with thermal imaging shows the method in action

What to Do If You Suspect Termites in a Wall

If your own checks turned up anything suspicious, the next moves matter — and the first rule is to resist the urge to start cutting.

• Don’t open the wall yourself. Cutting into drywall can disturb the colony, spread the problem, and make damage harder to assess. Leave that to the inspection

• Document what you found. Photograph the blistered paint, pinholes, frass, or mud tubes with notes on location. It helps the inspector zero in

• Don’t spray store-bought products into the wall. Surface sprays rarely reach the colony and can scatter termites to new areas, complicating treatment

• Get a professional inspection. A thermal-and-moisture inspection confirms whether it’s termites, how far it extends, and what species — which determines treatment. See Termike’s guide on what a termite inspection checks

• Find the source, not just the symptom. Termites in a wall connect to a colony elsewhere. Termike’s guide on how to find a termite nest covers tracing it back

The Bottom Line

Termites hide inside walls on purpose, but they’re not invisible if you know the signals. The practical answer to how to find termites in walls starts with your own senses: look for blistered or bubbling paint, tiny pinholes with frass beneath, faint mud tubes from baseboards or outlets, and sections that sound hollow or papery when you tap them, and listen for the soft clicking of termites feeding in a quiet room. You can do a methodical DIY sweep with nothing more than a flashlight held at a low raking angle and a screwdriver to tap and gently probe suspect wood, working room by room. But be honest about the limit — those checks only catch termites that have already left a surface clue, and many active infestations haven’t yet, which is exactly why professionals rely on FLIR thermal imaging, moisture meters, and acoustic detection to see the activity behind intact drywall. If anything you find looks suspicious, resist the urge to cut the wall open or spray into it, document what you saw, and get a professional inspection to confirm the species and extent. Catch it early and you’re dealing with a contained, treatable problem instead of a wall full of hollowed-out framing.

Frequently Asked Questions

How can I tell if there are termites inside my wall without opening it?

You rely on the surface clues termites leave and a few simple checks. Visually, look for blistered, bubbling, or uneven paint; tiny pinholes in drywall with a sprinkle of frass (what looks like sawdust or coffee grounds) beneath them; faint mud tubes emerging from baseboards, outlets, or along the wall; and any sagging or rippling. Audibly, tap along the wall, baseboards, and window and door frames with a screwdriver handle and listen for a hollow or papery tone that signals the wood behind has been eaten out — and in a quiet room, you may even hear a soft clicking or rustling of termites feeding. A flashlight held at a low, raking angle across the wall reveals surface irregularities that straight-on light hides. These let you detect likely activity without cutting anything. The catch is that early infestations often leave no surface sign at all, so the absence of clues doesn't guarantee the wall is clear — that's where a professional thermal and moisture inspection comes in.

Can termites be in a wall with no visible signs at all?

Yes, and this is the frustrating part. Termites feed inside wood from the inside out, often for months, before any evidence reaches the surface of a wall. In the early stages, there may be no blistered paint, no frass, and no visible mud tubes — the only hint might be a faint hollow sound when you tap, a single swarmer near a window, or nothing you'd notice at all. This is precisely why professional detection tools exist. FLIR thermal imaging detects the temperature differences created by termite activity and associated moisture behind intact drywall; moisture meters flag the abnormal dampness subterranean termites bring into wood; and acoustic equipment can pick up the sound of termites feeding inside the framing. These methods find active infestations that have left zero surface clues, which is why a professional inspection is the only way to be truly confident a wall is clear — and why periodic inspections matter even when nothing looks wrong.

Should I cut open the wall to check for termites myself?

No — resist that urge. Cutting into drywall to investigate usually causes more problems than it solves. It can disturb and scatter the colony to new areas, it makes the damage harder for a professional to assess accurately, and it can turn a contained issue into a bigger repair. It's also easy to cut in the wrong spot and miss the activity entirely while damaging a sound wall. Instead, document what prompted your suspicion — photograph the blistered paint, pinholes, frass, or mud tubes with notes on location — and avoid spraying store-bought insecticides into the wall, since surface sprays rarely reach the colony and can push termites elsewhere. Then get a professional inspection. A thermal-and-moisture scan can confirm whether termites are present and map how far the activity extends without opening the wall at all, so any cutting that does happen later is targeted and part of a proper treatment and repair plan. Termike offers free inspections — call (888) 683-3592.

What's the difference between how I detect termites and how a professional does?

It mostly comes down to seeing versus confirming. Your DIY detection relies on surface evidence and your senses: tapping for hollow sounds, looking for blistered paint, pinholes, frass, and mud tubes, probing suspect wood, and checking windows for swarmers. That's genuinely useful for catching an infestation that has started to show itself, and everyone should know those signs. A professional does all of that plus uses instruments that see through the wall: FLIR thermal imaging reveals heat and moisture patterns of hidden activity, moisture meters detect the dampness termites introduce, and acoustic devices can hear feeding inside framing. Professionals also know from experience exactly where termites concentrate — around plumbing penetrations, window frames, and sill plates — and can identify the species, which determines the right treatment. So your checks are the early-warning system, and the professional inspection is what confirms the diagnosis, its extent, and the solution. The two work best together.

Suspect Termites Behind a Wall? Get a Free FLIR Inspection

The surest way to know what’s behind the drywall is a thermal scan. Termike’s free FLIR inspection detects the heat and moisture signatures of termite activity inside walls — confirming the problem without tearing your home apart.

Call: (888) 683-3592

Or book online → Schedule Your Free Inspection