Mouse entry point

Rodent Entry Points

How Rodents Get Into Buildings

As we move into Autumn, the weather is starting to change. It starts to get a lot colder and there is a many more rainy days. It is now that we should be thinking about rodents. More importantly how could rodents get into your building or home by the use of rodent entry points. This blog is to inform you how rodents get into buildings and possible rodent entry points.

Air vents are common rodent entry points
Broken air vent allowing rat entry into the building.

Rodent Survey

As we get to the end of September we recommend to our customers to take 10 minutes to walk round their home. The purpose of this is to identify any possible routes of entry that mice or rats may take to get into your home or building. This can be anything from broken vents to unfiled holes where old waste pipes used to be. In commercial properties this may be poor fitting roller doors or breather holes in the walls.

Services entering the building. Rodent entry point.
Rats and mice use services into a building as a way to get in.

Rodent Body Size

We work on a two pencil width hole for a rat and a pencil size hole for a mouse. It may sound small but if you take the fur away then the actual body of a mouse is smaller. This is the same with rats, however they can also collapse their diaphragm so get through small holes. In both cases, if they can get their head through a hole then they can get the rest of their body through.

Rodent Entry Points

There are many different ways rodents can get into a building and the list is endless.  In the summer rodents are happy outside because there is lots of food about and its warm. In the winter it all changes, food sources deplete and it gets cold and wet. Rodents are opportunists and in general they are just looking to get warm and find food. If they come across an opening then the natural inquisitive nature will draw them in to take a look. When we do our survey we are looking for tell tale signs of activity. This can be a rat run or obvious trail, or smearing indicating a well used route. 

Rats follow waste pipes
Rats have found the route in beside the waste pipe.

Poorly Fitted New Pipes

Builders and tradesman have a lot to answer for when it comes to creating rodent entry points. They often use easy routes for pipes and cables and can be careless when drilling an access point. Not only this but they will not always finish off after or fill old holes no longer needed. If the building work is out of sight or tucked away, then some entry points can be left hidden.

rodent entry point from large pipe
The plumber has not filled in the hole after fitting this pressure valve outlet.Potential rodent entry point A new sink waste was fitted but the hole was not filled after.
An entry point for rodentss
Disused waste pipe hole offering an entry point for rodents

 Air Vents Make Good Rodent Entry Points

Air vents are a common cause of rodent entry, either through damage or old style vents. Victorian properties have air vents with large gaps which is more than ample as a rodent entry point. On modern houses the air vents are plastic, which is no problem for a rodent to gnaw to gain entry. Builders use them also as an easy way to direct pipes and cables in to the building.

Mouse entry point through air vent
Large gaps in the air vent allowing mice entry.
Rodents have gnawed the air vent
Air vent gnawed by a rodent.
mouse control
Builders used a vent for their vent

Foliage On Buildings Are Ladders

If you grow plants or climbers on the house you offer rodents a route up to the gutter. Once in the gutter they will find a route into the roof space. If you do then we recommend you trim it so it sits a foot or two below the gutter line.

rodents us foliage as a ladder.
Foliage growing up a house, rodents us it as a ladder,

Rats In Drains

Rats live in the drains and they will take advantage of any damage in the drain. They are natural burrowers and will follow a waste pipe into a house. They get into the fabric of the building and normally end up in the loft as it is a good place to hide out. We recommend you take a look in your drain every now and again to make sure everything is ok.

Rats in the drain
Hole in drain allowing rats to gain entry into the house.

Rodent Entry Points Via Doors

Mice like to take advantage in gaps in doors as shown in the picture below. Included in this is garage doors, especially when the garage is attached to the house as there are normally easy access routes into the house via cables pipes and wires. On commercial buildings, shutter doors are always an issue as they have normally been bashed about and dont create a good seal with the ground allowing rodents to get in.

mouse entrance by the gap in the door.
The gap in the door allows easy access to a building for a rodent.

Poor Tradesman’s Work

As mentioned previously, poor building works create an easy rodent entry point. Unfortunately trades people do not always consider the consequences of their actions or the problems that may cause. By not filling holes, blocking of drains or finishing correctly they are often the reason the rodent has made entry in the first place.

Lazy tradesman using a vent for a waste pipe
Tradesman has taken the easy option, but hasn’t taken off the vent cover and backfilled around it.
Rat entry into the house.
An easy rodent entry point into this building. It should be either filled in or fit a vent cover over it if it is a temporary hole.

Modern Buildings

Some new build houses and commercial buildings have breath holes rather air vents. All buildings need to breath so these holes are placed in the brick work to allow this to happen. The problem with this is it allows mice access in the cavity and once they are in they can make their way round a building undetected. Mice use the pipes and cables to navigate round a building once in. You can prevent this by fitting specially designed breather vents in the holes.

Mouse entry point via a breathing hole.
The breathing hole offers easy access for a mouse to get in the cavity.

What checks should be done to stop rodents getting in to your house.

When checking your property you should look for the following:

  • Broken vents and coverings
  • Poorly fitting doors and door surrounds.
  • Cracks in walls or brick work.
  • Holes from old services or pipes
  • Previous proofing work is still serviceable.
  • Recent building work to ensure tradesman have not left any poor standards of work.
  • Check inside drain cover for any earth, rubble or signs of digging.
  • Drain covers are fitted properly.

Having checked all the above and all is ok then you have done all you can to protect yourself. If you find anything from your survey then it is recommended that you carry out remedial works to repair the fault. A terrace or semi detached house is connected to others, so what happens next door is out of your control, but you must remember it is another route of entry.

If further help with either a survey or repair work we can help. We carry out all proofing works which can help to protect your building. To book a survey contact us and we can take a look.