poorly constructed pipework leaves an opening for rodents to gain access to this property

Rodent Entry Points

(Updated January 2024)

One of the most common questions our customers ask is: “How are rats getting in my house?”. After all, they’re large pests, so it can be hard to fathom how they entered your home without your knowledge.

Unfortunately, even the most vigilant of homeowners can get pests! Rodents can squeeze through tiny openings in places you wouldn’t even think to look at, like between exterior pipes and through drains.

So, to help you understand how they’re getting inside, we’ve written this helpful guide on rodent entry points, including signs to look out for and ways to prevent a rodent infestation.

How Do Rodents Get Into Buildings?

Rodents come in many different types, and many of them are skilled at entering homes through even tiny gaps. While the Rodentia family includes many different animals, the most common ones in the UK likely to be entering your property are rats, mice, and squirrels.

Rats and mice are capable of squeezing through tiny holes – no bigger than the width of one to two pencils. While this may sound ridiculous, when you think about the actual body of the pests and take their fur away, their actual width is much smaller than you would originally think. Rats are also capable of collapsing their diaphragm to get through smaller holes!

Since they’re even smaller, mice entry points don’t need to be very wide either. Generally, if rats, mice, and squirrels can fit their head through a hole, then their bodies will also be able to squeeze through.

rodents used their teeth to create this entry point into a home
Rodents gnawed their way through this vent cover to gain access to the property.

On top of their ability to squeeze through small gaps, it’s worth noting that rodents are naturally equipped with the tools required to enter almost any building they wish.

Armed with platinum-strength teeth and remarkable jaw power, plus their incessant need to gnaw on solid objects to keep their incisors down to a suitable size, rodents can create their own entry points. They will chew through brick, wood, concrete, and even steel to gain access to your property.

Why Do Rodents Enter Buildings?

Rodents will enter our homes and buildings for a number of reasons. In the summer, many rodents are content living outside thanks to the warm weather and abundance of food. However, as the seasons change, temperatures start to drop, and food sources become limited.

Rodents are generally opportunistic animals, always on the lookout for food, shelter and water to help them survive. If they come across an opening in the exterior of your home, then their innate inquisitive nature will draw them in to take a look.

Upon entering your property, if they find available food and water sources, then they’re likely to stay put. They will find a quiet and often undisturbed area of your home to make their nests, and before you know it, you’ve got a full-blown rodent infestation in your home.

How Do I Find Rodent Entry Points?

To find their route in, thinking like a rodent is required. Rodents want to travel in the shadows and move without being seen. Think about areas where your property is less busy and where people or pets don’t go. This will help you to identify some possible areas to check in more detail. A thorough inspection of vent covers, pipes, brickwork, and exterior doors should be carried out.

Many infestations are caused by rats in drains. It can be rats breaking out of the drains before they reach your property. Alternatively, if you have had work on your property and the drains have been altered in any way, they could escape inside your building.

Unfortunately, most builders don’t understand the capability of a rat, and we have seen some shocking practices that have left properties hugely vulnerable to rodent infestations, for example, redundant drains blocked off with plastic and waste pipes that are broken and left unrepaired.

hole left unfilled during construction creating a rodent entry point
This hole was left unfilled by tradesmen, resulting in a direct route for rodents to access the property with ease.

As such, a methodical check of your property is required to discover any potential rodent entry points. We recommend starting at ground level and working your way up. However, we realise that many areas can be difficult to reach without professional help, including rooflines and drains.

If you’re looking for a professional team to carry out a thorough inspection of your home, we provide in-depth rodent surveys and drain surveys here at Pest-Tech. Contact us today to book your survey, and we’ll help you uncover all potential rodent entry points on your property in no time.

Common Rodent Entry Points

There are some common entry points for many different types of rodents. Whether it’s mouse entry points or squirrels climbing onto your roof, there are many different ways rodents can move into your space.

Poorly Fitted Pipes

Builders and tradesmen have a lot to answer for when it comes to creating rodent entry points. While many are highly professional and great at their jobs, some use easy routes for pipes and cables and can be careless when drilling an access point. In addition to this, they may not always finish their work properly and forget to fill old holes that are no longer needed. If the building work is out of sight or tucked away, then some entry points can be left hidden from humans, but not rodents!

rodent entry point from large pipe
Rodent entry point through a large pipe

Air Vents

Air vents are a common cause of rodent entry, either through damage to newer vents or natural gaps in old-style vents. Victorian properties have large gaps in air vents, which are more than ample as a rodent entry point. In modern houses, the air vents are plastic, which is no problem for a rodent to chew to gain entry. Some builders also use them as an easy way to direct pipes and cables into buildings, again leaving gaps that rodents can squeeze through.

rodent entry point air vent
A Victorian air vent with gaps large enough for rodents to pass through.
Air vent gnawed through by rodents to gain entry to a property
Rodents have gnawed through this plastic air vent to create an entry point into this property.

Overgrown Shrubbery

If you grow plants or climbers on the house, you may accidentally offer rodents a route up to the gutter in the form of a stand-in ladder. Once in the gutter, they will find a route into the roof space, often chewing their way through your fascias and soffits to gain access.

overgrown shrubbery used by rats to gain access to properties
Rodents use this overgrown foliage as a ladder to access the property.

Not only does this grant rodents an easy way of entering your home, but it also results in damage to your guttering systems that can be costly to repair. If you have climbing plants like ivy, for example, then we highly recommend regular trimming to keep the plants sitting at least a foot or two below the gutter line. If you have overhanging tree branches, these can be used by squirrels to gain entry to your home. So, whatever rodent problem you have, overhanging greenery could be the cause.


This is more specific to rats, as they often live in drains. Rats take advantage of any damage in drains. They are natural burrowers, so they can easily follow a waste pipe back into your home.

holes in a drain allowing for rodents to gain entry
A hole in this drain system allowed rodents to gain access to the property.

If you’ve recently had any alterations to your drain system, such as moving a bathroom from downstairs to upstairs, then you or your contractor may have left a gap that could lead to vermin entering your home. To ensure these gaps are sealed promptly, we highly recommend a rat drain survey to check for ingress points that could lead to a rodent infestation.

External Doors

Small gaps and poorly fitting external doors or windows make easy entrance routes for mice, rats, and squirrels. We regularly see gaps in garage doors where the garage is attached to the house. Once inside the garage, the rodents can gain access to the main home via cables, pipes, and wires.

A door with a broken seal allowing access to rodents.
The seal on this door had gone, leaving the perfect gap for rodents to enter.

In commercial buildings, shutter doors are commonly used by rodents. Once the seal between the door and the floor has been broken via wear and tear, the gap created produces an easy way in for rodents.

Poor Construction Work

As mentioned previously, poor building works create an easy rodent entry point. Unfortunately, tradespeople do not always consider the consequences of their actions or the problems that their less-than-adequate work may cause. By not filling holes, blocking off drains or finishing tasks correctly, they leave plenty of gaps around your home that rodents can use to gain entry.

disused pipe not covered or filled in results in a rodent entry point to this property
This waste pipe was no longer needed, yet it was never blocked off or filled in, leaving an open rodent entry point on the exterior of the building.

Holes In Brickwork

Many modern buildings, including new build houses and commercial buildings, have breathing holes rather than air vents. All buildings need a steady flow of air, so these gaps are placed in the brickwork to ventilate the property. Unfortunately, the problem with this is it allows mice, rats, and squirrels access to the cavity. Once they are in, they can make their way around your building using gaps in cavity walls, pipes or cables and go virtually undetected.

A breathing hole in the brickwork of a new building creates access for rodents
This breathing hole in a new building allows rodents access into the cavity.

How Do I Stop Rodents Using Entry Points Into My Home?

There are a number of things you can do to fix existing rodent entry points, prevent new ones from forming and protect your property from the threat of rodents.

The first step is to carry out a thorough investigation of the full property looking for common signs of rodent activity, paying particular attention to the following:

  • Broken vents and coverings
  • Poorly fitting doors and door surrounds
  • Cracks in walls or brickwork
  • Holes from old pipes
  • Recent building work to ensure tradesmen have not left any potential entry points
  • Inside your drain cover for any earth, rubble or signs of digging
  • Drain covers to check they are fitted properly

If you discover any signs of damage or gaps wide enough to fit a small rodent, then it’s vital that you carry out remedial work to repair the fault as soon as possible. Here at Pest-Tech, we offer a wide range of rodent-proofing techniques designed to suit all types of properties.

If you’ve found any rodent entry points on your property, then it’s also highly likely that you’re suffering from an active rodent infestation. Mice and rats don’t wait and may already be inside your property. Signs such as gnaw marks, urine stains and droppings could indicate that you have rodent problems.

Even if you see signs of rodent activity, there’s no need to panic; we offer effective rat controlmice control, and squirrel control services to homes and businesses across Maidstone and Kent.

To book your site survey, simply call 01622296055 now or email the team at admin@pest-tech.org. As part of our expert rodent control service, we’ll identify all potential rodent entry points on your property and then work to get rid of your infestation for good.