How To Know If Roaches Are In Walls For Sure – 3 Signs

When roach infestation is in your home is moderate or severe, roaches can hide in the tiniest of space they can sneak in.

And the gaps in the walls and ceiling in your home are no exception.

In this guide, you’ll find out how to know if roaches are in walls.

You’ll learn three telltale signs that will confirm roach presence in the walls.

You’ll also learn how to get rid of roaches in the walls.

Keep reading.

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How To Know If Roaches Are In Walls – 3 Signs

How to know if roaches are in walls

Cockroaches are nocturnal. Most of the scavenging work roaches do at night.

During the day, roaches prefer to lay dormant and hide. At night they come out scavenging for food. 

And that makes you wonder why there’s a sudden appearance of cockroaches in your home.

Cockroaches will hide in the darkest corners of the home that are hard to access.

From deep inside into the kitchen cabinets to drains, cockroaches will hide anywhere where they can find water, food, and waste.

On the walls, roaches look for tiny gaps and crack to hide. 

Here are the three signs of roaches in walls –

Physical Sighting Of Roaches Crawling In and Out Of The Cracks In The Wall

There’s no sure-shot sign of roaches in walls other than physical sightings of alive cockroaches coming in and out of the walls. 

Now, what type of roaches will choose which rooms to hide depends on the roach species.

For example, walls belonging to areas of your home with high dampness, like the bathroom and kitchen, will harbor oriental roaches and American roaches.

It’s because these roaches prefer to hide in highly moist areas.

In contrast, walls belonging to dry rooms of your home, like the bedroom and living room, will harbor the German roaches.

Cockroach Smear Marks On The Walls

Cockroach smear marks on the walls

You might not see alive roaches often in the thinnest of gaps in the walls.

It’s because they’ll hide deep inside the gap during the day.

But cockroach smear marks on the walls are an undeniable sign of roach presence. 

You’ll find roach smear marks on the walls of damp places in your home, like on the walls of the bathroom, basement, kitchen, and laundry room.

These smear marks are cockroach poop.

And cockroaches that live in damp places, such as the American roach and the oriental roach, discard liquid poop in the form of smear marks.


It’s because they eat wet filth.

Roaches can defecate near and on their nests or hiding place.

They do it to communicate with other roaches and, the baby roaches in the nest eat the roach poop.

Sounds From Inside The Wall

Now don’t get this wrong. Roaches that infest homes don’t make sounds audible to humans. 

But roaches crawling inside the wall can produce a chirping sound which at times is audible. 

That happens when there are many roaches or an entire colony of roaches hiding in the walls. 

In a home with a heavy roach infestation, this is quite common, especially behind false walls and false ceilings.

The area behind wallpapers and false walls are ideal places for the roaches to hide. 

Give these roaches the tiniest and the thinnest of gaps, and they’ll capitalize on the opportunity to sneak in and hide.

Now that you know the signs of roaches in the walls of your home, it’s for the next step. 

That is to get rid of them in the walls.

The following section covers it.

How To Get Rid Of Roaches In The Walls In 5 Steps

How to get rid of roaches in walls

Getting rid of roaches in the walls is an easy task. 

But there’s a catch.

Roaches in the walls are a clear indication of heavy roach infestation. 

So, getting rid of roaches only in the walls isn’t a long-term solution against the roach infestation in your entire home. 

You can read our guide on cockroaches and how to get rid of roaches after finishing this post. You’ll get in-depth know-how to get rid of cockroaches in your home.

Coming back to getting rid of roaches in the walls, here are the 5 steps –

Fix Any Water Leakages Around The Walls Where Roaches Hide

The bathroom, kitchen, and basement are already damp because water usage in these places is relatively higher than in other rooms of your home.

Water leakage in the plumbing area of these rooms in your home is quite regular.

And American and oriental roaches love to hide and nest near damp places.

So, the first step is to fix the water leakages. 

That’ll deny the roaches the amount of water they need to survive. 

Clean The Rooms Where Roaches Are Hiding In The Walls

Roaches feed on filth and organic waste. That’s why your bathroom and kitchen are the prime places for cockroaches to hide.

Both these areas of your home have an abundant supply of food waste and organic waste like hair and nails. 

Clean these places and ensure that there are no food stains left behind. Food stains and edible oil stains attract roaches too. 

It’d be best if you use a disinfectant mixed with peppermint essential oil to clean the hard surfaces of the rooms where you’ve spotted roaches in the walls.

Roaches hate the smell of peppermint oil and eucalyptus oils. It repels them.

Cleaning the rooms whose walls are harboring roaches will cut off the supply of food to these roaches.

Spray An Anti-Roach In The Gaps And Cracks Of The Walls

Now that you’ve denied roaches both water and food, it’s time to get on the offensive. 

And the best way to do it is to spray a lethal and strong anti-roach spray like Ortho Home Defense in the gaps of the walls to kill the roaches.

Ortho Home Defense spray kills roaches on contact instantly. 

But please do read the instructions on the label and take the necessary precautions while using the spray. 

Keep Cockroach Baits To Trap And Kill Roaches That Escaped

cockroaches stuck on cockroach bait

Roaches are slimy creatures. 

In the above three steps, there must be a bunch of roaches that might have escaped, which you would overlook. 

Leaving them alive isn’t a good option because these roaches will find new hiding places in your home. 

And they’d start to breed and spread fast. 

Cockroach baits come in handy to tackle the problem. 

Cockroach baits will lure the roaches that escaped. These roach baits contain roach-killing poison, which is lethal for them.

Keep these roach baits near the gaps and cracks on the walls where you’ve spotted the roaches.

Also, place the baits on places where roaches scourge for food. 

Some places to keep baits are below the sinks, near the oven and stove, below kitchen countertops, inside the bathroom vanity, and near your bathtub and toilet basin. 

But if you spot any alive roaches, either squish it to death under your shoes or spray an anti-roach spray directly on it. 

Finally, Seal The Gaps And Cracks On The Walls

Once you’re through with the above steps, you’d find dead roaches all around and inside the gaps of the walls.

Get rid of the dead roaches because dead roaches attract more cockroaches

Pull out the dead roaches inside the gaps on the walls with a fork, and discard them.

Now, seal those gaps and cracks on the walls with a silicone-based sealant

You would need a caulk gun to do the sealing. 

Silicone-based sealants are strong, and they last for at least a decade. 

The best part is roaches can’t eat through it. 

How To Kill Roaches Behind False Walls?

When it comes to roaches living behind false walls, things might not be as straightforward as killing roaches in the gaps and cracks of the actual walls.

You’d need to tear down the entire false wall and spray an insecticide spray on them. 

But in most instances, a massive number of cockroaches hide behind false walls. 

And that means heavy roach infestation. 

When there’s a heavy roach infestation inside your home, hiring a pest controller is always the best choice. 

It’s because roaches are tough, and they don’t die quickly with natural methods. 

Also, the effect of natural methods takes time. 

When the infestation level is low, then you can use natural methods to kill and repel roaches. 

But with a heavy cockroach infestation, it’s not a good idea to use DIY or natural methods to get rid of roaches. 

They won’t work. You’d need an expert to do the job. 

That’s why we didn’t recommend any natural methods to get rid of roaches in the walls. 

In a way, roaches in the walls are a sign of heavy roach infestation. 


Here’s how to know if roaches are in walls –

  1. Physical sighting of roaches crawling in and out of the cracks in the walls.
  2. Cockroach smear marks on the walls.
  3. Crawling sounds of roaches from behind the walls.

But keep in mind that roaches don’t make any sound. Their crawling and digging inside the wall can create a sound.

In this guide, we revealed 5 steps to get rid of roaches in the walls. 

As you figured out in the post, roaches in walls can signify heavy roach infestation. 

So, getting rid of cockroaches hiding in the walls is a stop-gap solution.

It’s not the solution to roach infestation in your home. It’d be best to hire an experienced and reliable pest controller to do the job. 

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