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How Do I Get Rid of Rats in Cavity Walls?

get rid of rats in cavity walls
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    Most structures within urban settings will have a cavity wall at some point throughout the home. These types of walls are usually brick and have advantages related to rain and wind as well as superior insulation benefits. On the downside, a cavity wall has a hollow center, which can be a safe nesting area for rats and rodents. Rats and mice can enter into a home through openings like holes and burrows under the walls.

    So, how do I get rid of rats and mice in cavity walls? To get rats out of cavity walls, a full inspection of the wall cavity needs to be conducted. Seal all entry holes present and make sure you apply concrete at the baseboards of the wall to prevent rats from burrowing into the home. You can also set traps in the cavity to decrease the rodent population.

    There are benefits to having a cavity wall but there are also drawbacks like the development of a rat problem. Removing rats from the wall cavity is conducted much like other rodent removal measures, but there can added difficulty due to the inaccessibility of the space. This article will go over the options you have to remove and prevent a rat problem, as well as the benefits of considering pest controllers to handle the situation.

    How Do Rats Get in the Cavity Wall?

    A rat problem is a serious matter and this is because rodents are versatile creatures that will find a way to get the nourishment and shelter they need to survive. Even pest control professionals become amazed at how versatile these pests are.

    Rats will naturally make nests in cavities between two walls since this is usually an inaccessible and peaceful place. Since this will not keep them safe from inclement weather, rats will seek to move indoors either through the attic, drains, and areas underneath the wall that are easy to burrow through. Rats can even chew holes through air bricks if your building uses air brick.

    Since there are many ways in which rats can get inside the home through the cavity wall, let’s explore the most popular ways in-depth.

    Chewed Air Bricks

    Plastic air bricks are becoming more and more popular as a brick alternative. These types of bricks are eco-friendly, lightweight, and provide good insulation for the interior of a building. Unfortunately, the durability of the material makes air bricks easy for rats to gnaw through the brick and enter the property.

    The only real way to prevent rats from chewing through air brick is to remove the rats completely with the assistance of pest controllers. Once the rats are removed, there are a few preventative measures you can apply to keep future rodents from chewing through the brick and entering your home.

    Applying a stainless steel mesh around the brick can prevent the rats from chewing and thereby damaging the brick and entering your home. Make sure to spread the steel mesh around the entire vicinity of the brick and this will keep the rats from entering your property through this entry method.

    Holes in Walls

    Holes in the walls are also an easy and common entry point for rats into a building. As buildings age and settle, even the tiniest of holes that form can be enough for a rat to enter inside. The only solution for stopping rats from entering through a hole is to seal it, which can be done with a tool like cement or any type of drying agent that will thicken and prevent the rats from chewing through it.

    It is important to make sure that all holes are sealed shut and it may help to place steel mesh around the cavity wall to ensure rats cannot even access the wall in the first place.

    Burrows Under the Walls

    If the foundation under your walls is dirt, then this can spell bad news for attempting to keep the rats from simply burrowing under the dirt to enter the other side and into the property. If the floor of the hollow cavity between the walls is cement or some other inaccessible foundation, then this possibility is usually not a viable entryway.

    Once a rat discovers that the foundation is pliable enough that they can gnaw and dig under it, the rodents will relentlessly dig and tunnel under the foundation to find a way inside. There are a few things that you can do to ensure that rats are not able to do this.

    One solution is to dig below the surface until you reach the foundation and then consider placing wire mesh in this area that wraps around to the front side inside of the home. Granted, rats will find this task to be incredibly difficult and time-consuming, but if they are determined to find a way in, they will proceed and keep tunneling.

    More often than not, rats will try and find a shallow alternative near the corners of the wall to reach the other side. This is almost always provided for if drainage faults are located in the wall cavity.

    Drainage Faults

    Drainage faults that can exist when the brick in a cavity wall begins to ride our crack due to the moisture can become easy entry points for rats to enter and exit the home. You can easily find these cracks and faults in the foundation in the areas where drainage lines appear, and chances are, you may find small holes that rats can enter and easily gnaw through the interior wall to enter the inside.

    Fixing these holes simply requires a strong and durable sealant to close the hole and eliminate the entry point.

    How Do I Get Rid of Rodents in My Wall Cavity?

    The only real way of getting rid of the rats is through removal, but the wider issue when it comes to rats is the attractants that draw them to a home in the first place. If you can make your wall cavity as inhospitable to rats as possible, you will not only prevent rats from coming, but you may also get existing rats under control.

    There are certain things that will cause rats to take up residence somewhere, so if you can remove these common causes of rat infestations, you will be halfway to having your rat problem under control.

    Even though it would not be easy to remove the cavity wall, there are still certain things that will keep rats encouraged to find a way inside of your home. Rats need three things in order to live in an area: Shelter, food, and water. If the rats do not have access to these things, they will not want to live on your property.

    Preventative Measures

    You should clear any areas of vegetation, wood, or debris surrounding or touching your house, as well as any clutter inside. This will work to keep the rats from even wanting to approach the cavity wall to find a way inside. But it could also be possible that the rats are not even entering through the cavity wall and are just using it as an extra way to get back outside!

    If you can, thoroughly check the hollow area inside of the cavity as well as any outside buildings for possible rat hiding spots, and clear them of any clutter. Check around the outside of your home for possible access points that rats could enter by, remembering that a rat can fit through a gap as small as one inch, so be sure to check for gaps under doors, and chinks in bricks. You can buy flexible seals to put under doorways to help prevent rats from entering.

    Make sure all food and trash are sealed tightly, this may mean using metal bins with firmly fitting lids and putting dry foods in sealable containers instead of plastic packaging. Check all of your plumbing and drains, specifically any near or within a wall cavity, to make sure there are no water leaks and don’t leave any water sitting out; rats, unlike other rodents, will not stick around if they don’t have consistent access to water.

    You can also buy chemical rat repellents to place within the hollow cavity. Following these steps should help prevent any rats from wanting to share your living space and help control an existing rat problem.

    Poisons and Traps

    If preventative measures aren’t enough, you may need to take more aggressive actions against the rats. There are many kinds of poison and rat traps that can be very effective and controlling a rat problem, but they don’t come without a negative gross-out factor.

    If you choose to use poison, you need to make sure the poison is out of reach of any household pets, as it is equally as toxic to them as the rats. There are, however, many devices that will allow rats to reach the poison, without making it accessible to other animals.

    Another problem to be aware of when using poison in a hard-to-reach area like a wall cavity is that if a rat eats the poison and dies in the cavity, you may have to deal with the smell of a decaying animal for longer than you’d like.

    There are also several types of traps, but they are not for the faint of heart. The main varieties are Kill Traps, Catch-and-Release Traps, and Glue Traps. Kill Traps will kill a rat instantly and are oftentimes more humane than other methods, though you will have to dispose of rat bodies. Catch-and-Release traps, also known as Live Traps, catch the rat without harming it so that you can relocate it to another area.

    With these traps, you should check them at least once a day, and you will need to relocate any live rats you catch. Glue traps are extremely effective, but are also considered to be very inhumane; they work by catching the rat in a patch of extremely strong glue, rendering it unable to move. With these traps, after catching a rat, which will often be in distress, you will need to kill the rat and dispose of the body.

    For the easiest, safest, and most effective removal method, consider allowing pest control professionals to handle this tricky situation.


    Can Rats Climb Up Cavity Walls?

    Rats are expert climbers and are biologically equipped with claws and feet that are designed to scale vertical walls to enter structures that would commonly be inaccessible for other animals, such as roofs and attic entry points.

    Rats have edgy pointed claws at the tips of their feet, which combined with legs that are light and made for climbing at a fast rate, enables rats the ability to scurry up the side of a building if they are inclined to do so.

    It could be that the entry point into your home is not a hole or a burrow in the cavity wall, the rats are simply using the cavity wall to enter a point in the rood that allows them to enter the home through the attic. This is why it is important to do a full inspection of the entire home or building to find any and all possible entry points for rats.

    How Do You Tell if You Have Rats in Your Walls?

    You can typically hear rats inside of the walls. If all indoor appliances are turned off and it is quiet, you can hear the rodents scurrying inside of the walls. Another warning sign is the appearance of rat feces around the walls and also the appearance of holes that were not there previously.

    Holes are usually the easiest rat indicator.


    If the methods listed above aren’t working, or you simply do not want to deal with the hassle of trapping and disposing of rats, or of having poison on your property in a hard-to-reach area like a cavity wall then talk to Malum Pest Control based in Southampton.

    Our pest control specialists will be able to get your rat problem under control with little effort on your part. We can also give you advice on how to control rats in the future. In fact, this is often the best course of action, because you can be assured of a solution, without risking the rat infestation getting out of control.

    Picture of Dean McFarlane
    Dean McFarlane
    Dean is an expert pest control specialist and has been providing pest control services for over 10 years. His company Malum Southern Pest & Bird Control can deal with a wide range of pest problems and is available 24 hours a day 7 days a week.

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    We are experts in private and commercial pest control in Hampshire, Dorset and West Sussex. If you think you have a problem with pests call us for a quote.

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