There are two things you need to know about rats; 1. They only need a very small hole to gain access to your property, and 2. Rats can chew through almost anything to get there! Now you are hearing scratching inside your walls. It might be rats! But how DID the rats get in the cavity walls?
What is a cavity wall?
A cavity is a gap between the two skins of brickwork. The gap exists to ensure water is not transferred from outside the house to inside.
The outer layer of bricks absorb the water and as it passes through, the water drops to the ground and not into the house.
How Rats Get in the Cavity Wall – 5 Common Ways
1. Roof Edges
This is a very common way for rats to get in your cavity walls, especially if you have overhanging trees next to your property.
Rats can easily climb trees and as soon as they get onto your home, they will look for a weakness to exploit to gain entry.
The joint between your roof and walls is likely to have some gaps in that are big enough to fit a rat in. There is good news, it is easy to avoid this by ensuring there are no hanging trees on your property, and ensure there are no other ways a rat can access the top of your house.
2. Venting Systems
Venting systems will pass through the brickwork of your home, and if they are not installed correctly they could leave gaps that can easily be used by rats.
You will need to check the venting system for any potential flaws in the installation. If you find any, it is a very good idea to close them. It will help stop rats from getting into your cavity walls and will also help keep your home warm in the winter!
3. Weakness in Masonry
Over time, the mortar between bricks becomes weak and will crumble away.
Gaps between bricks offer a rat the opportunity to enter your house and set up home in your cavity wall.
It is very important that you regularly assess your home for weak mortar and call in an expert to re-point for you to ensure any rats cannot get in.
4. Air Conditioning
Air conditioning units need to pass through your walls to the outside, which will give a rat the opportunity to find a weakness to exploit.
Pipes and cables need to be passed through to the outer layer of your property and the installation may have left small gaps that can easily fit a rat into. It is time to get the ladder out and check for gaps to plug!
5. Cable Holes
Many homes have cable or satellite television. In order for the cables to reach the inside of the house, there needs to be a hole to pass the cables through.
Rats only need a very small hole to enter your building and cable holes are certainly big enough.
If this route into your house is used by a rat, you are likely to get some warning signs, especially as they would have chewed through the cable! An early warning sign would be an inconsistent television signal, or maybe no signal at all.
Check your cables for signs of chewing.
Why you do not want rats in your cavity walls
There is one very good reason why you do not want rats in the cavity walls, and it is the same reason why you should not use rat poison! When a rat dies in your cavity wall, it will decompose.
Finding the rat was very easy, it was a simple case of following my nose in the attic. Find a dead rat in your cavity walls is going to be a much more difficult task.
You will no doubt need to enlist the help of a professional.
How to Get Rid Of Rats in the Walls
If you have noticed that you have rats in your cavity walls, then I am certain that you will need to know how to get rid of them.
Basically, you have three options:
- Damage the wall – this should be the last resort because it will cost you a lot of money to fix!
- Tempt the rat out – tempting the rat out of a hiding place is relatively easy, it just takes time and patience. You should set some humane traps with some rat bait near any entry point to the wall. The rat will smell the bait and will eventually find it, getting trapped in the process. For a rat to be tempted to leave the security of the cavity wall, you cannot be in the vicinity of the wall. The rat will sense that you are there and will not come out. I suggest that you set up the traps and leave home for a few hours.
- Wait for the rat to leave the walls – This is similar to the option above, and also involves setting up a trap. The only difference is that you set the trap up and go about your daily business. Rats do not stay in the walls permanently, they have to venture out to find food and water. When they venture out of your cavity walls, they should be tempted by a trap that you have set up nearby. This is likely to happen after sundown when you are asleep, so check in the morning.
There are many ways that a Rat can get in the cavity walls. The 5 above are the most common.
The important thing is that you regularly carry out maintenance on your property to limit a rat being able to gain access in the first place.
Every few months you should be performing a routine check on the outside of your home. Check for holes, for weak points, and anything that needs to pass from the inside of your house to the outside. Look at cabling and look for pipework. Record all rat entry points and make a checklist that you can use for each check.
The last thing you want is a rat dying inside a cavity wall!