Malum Pest Control Services

How to stop rats from chewing wires

How to stop rats from chewing wires
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    The Latin translation of the word ‘rodent’ is ‘to gnaw’. If you’ve ever noticed the tell-tale sign of bite marks on electrical wiring in your house, then it’s likely that rats or mice are to blame. Aside from the costly damage caused, it is potentially hazardous. But how and why do rodents chew electrical wiring, and what can you do to prevent it?

    Rats chew wires to grind down their teeth, which never stop growing. This can cause electrical problems and create a serious fire hazard. There are various methods of rodent control to prevent rats chewing wires, including sealing gaps to prevent them entering your house.

    If you suspect a rat problem in your house or commercial premises, then it’s best to take swift action. The team at Malum can offer a professional, three-visit pest control service to rid your property of rats and mice and prevent them from coming back.

    Why do rats chew wires?

    There are a few theories as to why rodents seem to find electrical wires irresistible.

    It’s likely that in some cases, rodents chew on wires simply to get from A to B, chomping their way through any obstruction. A rat’s perseverance should not be underestimated when it comes to finding a desirable nesting place, and a few wires along their path is unlikely to deter them.

    Some have suggested that the shift to using renewable materials in the past decade or so is also a cause of rodents chewing wires.

    The majority of car wires are now coated with soy or other plant-based material, which of course makes them all the more palatable. Tempted in by the cosy, dark environment of your car bonnet, rodents will think they have hit the jackpot with a new home, playground and food source all rolled into one.

    They will soon make a meal of your car wires, causing costly and potentially hazardous damage.

    The most likely reason for rats and mice chewing wires is to maintain their teeth. Rats teeth never stop growing, much the same way as a human nails. If a rodent’s teeth get too big, it can affect its ability to eat, so their instinct is to gnaw to grind the teeth down and sharpen them all in one go.

    Electrical wiring is just the right size and shape for rat claws and jaws and offers them the perfect opportunity to get their teeth around something.

    What happens if a rat chews through electrical wires?

    Rats and mice on your property is never good news due to the disease they spread, but if they decide to feast on the electric wiring in your house then it creates a whole host of other issues. The protective insulation around electrical wire is no match for sharp rodent teeth, and live wire can be left exposed in no time.

    When that happens, there is a strong chance of neutral and live wire touching, leading to a short circuit. This is more than likely to trip the circuit, leaving you in the dark. But that is nothing but a minor inconvenience when you consider the expensive damage to appliances a short can cause, not to mention the increased risk of electrical shocks.

    In the most serious scenario, a spark from an exposed wire has the potential to start a fire. It’s thought that a large percentage of unexplained house fires in the UK could be down to rodents chewing wires. In most buildings, electric wiring is hidden away in walls, floors and lofts, out of everyday view, so a tiny spark can go undetected with devastating consequences.

    It’s also worth remembering that most home and business insurance policies do not cover damaged electrics when rodents are to blame, so you could find yourself footing very expensive repair bills if rats and mice take hold.

    That is why it is essential to take action right away by contacting a pest control expert such as Malum. We can rid your building of mice and rats and provide valuable advice on how to deter rodents from your property.

    What are the signs of rats chewing wires?

    The most obvious sign that rats have been chewing wires is their bite marks on the insulation and the exposure of the live wire underneath. It’s a definite sign that rats have been, and are likely still to be, on your property.

    But, if you don’t have access to all of your wiring the damage can be difficult to detect. It’s not until the lights go off, your appliances stop working or cause a nasty electric shock that you may realise there’s a problem at all.

    Fortunately, there are other common signs of a rat infestation to look out for, to nip the problem in the bud and prevent further rodent damage before it gets out of control.

    Look out for signs of rats and mice:

    • Rodent droppings are around 1-2cm long and appear dark brown when fresh, almost like a raisin. As the droppings age, they become white-ish and dusty.
    • Grubby marks on walls and floors can indicate a rodent has rubbed up against them.
    • Rodent nests can be made from material scavenged from your car or property, such as loft insulation, food packaging and paper.
    • Footprints and trails left by tails are also a good indication you have unwanted rodent guests.
    • Evidence of burrowing around the perimeter of your property suggests that rodents are nearby and are no doubt investigating entry points into your property.

    Ways to deter rats from chewing electrical wiring

    When it comes to rodent damage, prevention is certainly better than the cure. As a property owner, you should consider taking precautionary action to stop rodents getting into your building and chewing your wires.

    Seal up entry and exit points

    Rats do not require a red carpet to enter your property – they are determined to seek shelter, especially in winter, and tiny crack or crevice of a couple of centimetres will do.

    Fill any holes and gaps with expanding foam or another type of filler to limit their access points.

    Don’t forget your loft space, as it is easily accessible, especially if you have trees or shrubs nearby.

    Use deterrents and/or traps

    For many, traps are not an acceptable option, but they needn’t be deadly. A more humane method to see rodents off is with the use of a special sonic deterrent.

    Designed so that only rodents can hear them, humans and domestic animals will not be disturbed.

    Remove attractive food waste

    Rats will nest as close to a food source as possible, so it’s vital to seal food waste securely to keep their enquiring noses out, and of course dispose of it frequently.

    Protect wires in coatings or seal them

    A rat can chew through the toughest of substances, but even they will balk at wiring coated in concrete, even just a thin layer.

    Alternatively, consider sealing wires in metal or plastic cable sleeves.


    Do mice chew electrical wire?

    Although rats most often get the rap for chewing through domestic and car wires, mice are just as guilty.

    The only real difference to the damage they can cause is due to their smaller size, but it only takes one bare wire to cause serious damage.

    So it’s vital to take action to prevent mice from taking up residence in your building.

    Can rodents chew through cement?

    Even rodents will give up chewing when faced with concrete, so setting wiring in cement is an effective way to stop rodents damaging them.

    How do you fix a chewed wire?

    If you notice damage to electrical wires and suspect rodents, then it is best to get a professional electrician to inspect your property and determine the scale of the damage.

    In the meantime, cover any exposed live wires with electrical tape to avoid them sparking, first ensuring that your electric supply is switched off.


    The best defence against rodents entering your house or business premises and chewing through your wiring is to remain vigilant and take fast action.

    Look out for the signs and take preventative measures to make your property and vehicles less attractive to rats, mice and even squirrels.

    If the problem has already taken hold, then a professional pest control service is advised to eliminate the infestation and to prevent rodents from returning.

    Contact Malum Southern Pest and Bird Control for rodent control

    The team at Malum provide professional, effective, safe, and cost-efficient solutions to take care of all pest control needs.

    We have a great deal of experience when it comes to rodents chewing wires, and can identify the source of the problem, fast.

    We are advocates of taking action in preventing rodents before they cause serious damage, and offer valuable advice as part of our service.

    Contact us today if you have a problem with rodents chewing wires for more advice and a pest control quote.

    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.

    Request a quote today

    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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