8 Ways To Tell if Mice Are Chewing on Wires

by Derrick | Last Updated: September 7, 2021

Mice and rats are a common household nuisance, and chewing on wires and cables is one of their favorite pastimes. Unfortunately for us, mice chewing on wires can have detrimental effects on electrical systems in our homes, even causing fires in extreme cases. So, how can you tell if mice are chewing your wires ?

There are eight ways to tell if mice are chewing on wires, such as:

  1. There are bite marks on your wires.
  2. You notice mice droppings around your house .
  3. You hear scratching and skittering nearby.
  4. Your lights start to flicker.
  5. You suddenly experience power outages and breakers tripping.
  6. Chewed wires caused a fire accident in your home.
  7. There are signs of mice nests .
  8. You see a mouse chewing on your wires.

In this article, I’ll discuss how to tell if mice or other rodents are gnawing on your wires and what you should do to stop it from happening again.

Why Do Mice Chew?

Mice will chew anything they can chew, including wires and other household items. Rodents like mice, rats, and even rabbits have teeth that grow for their entire lifetimes. To ‘trim’ their teeth and keep them from getting uncomfortably long, they’ll chew on things to dull their teeth. 

Wires are attractive to mice because the uniform shape of the wires makes it easy for the mice to grip and chew. If wires are left anywhere, mice or rats can get to them. Chances are they’ll use the wires as a teeth trimmer! Even worse, mice will chew on a wide variety of materials and are fully capable of leaving large holes in things you’d consider impenetrable.

Other Things Mice Will Try To Chew:

  • Wood
  • Plastic
  • Drywall
  • Cardboard
  • Rubber
  • Fiberglass

Mice are fully capable of identifying the crevices and weaknesses around your home that they can chew their way through, gaining access to the shelter of your home and the resources inside – food and water, namely. Still, other things to chew on are a plus in their rodent minds.

How To Tell if Mice Are Chewing Your Wires

Thankfully for us, there are quite a few telltale signs that mice or other rodents are hiding in or around your home and using your stuff as their chew toys, along with the obligatory food theft. Below are 8 ways to tell if mice are chewing on wires:

1. There Are Bite Marks on Your Wires

This is the most telltale clue you’re likely to come across, and perhaps even what led you to this article. Bite or gnaw marks on cords, cables, and loose wiring are very concerning, especially if you don’t have any existing pets that could have done it by accident. The bite marks are tiny, but mice are fully capable of chewing through an entire wire. 

2. You Notice Mice Droppings Around Your House

Another easy-to-miss clue that signals the presence of mice is finding their pellet-like droppings around your home. They can be found anywhere, but the most likely places are where you keep food, or behind furniture, boxes, baseboards, or other small and dark places mice could hide.

3. You Hear Scratching and Skittering Nearby

Mice are very stealthy critters, but they still make noises. Scratching can be a sign of mice trying to destroy something, perhaps creating an opening in a weak patch of drywall. Skittering sounds can be heard when you’re near one or more mice quickly moving – you’ll hear it if you’re near their nest!

4. Your Lights Start To Flicker.

If your lights recently developed a habit of flickering oddly, mice chewing wiring may be to blame. You should be worried if mice get behind insulation and where the wiring for your lights is – they’re perfectly capable of chewing the wiring. There’s still hope at this point – flickering lights mean that the wiring is partially damaged and that it’s not destroyed yet. 

5. You Suddenly Experience Power Outages and Breakers Tripping

Mysterious power outages and breakers tripping for no reason can be annoying or have you wondering if a ghost is messing with you. In reality, it could be something as irritating and real as a mouse chewing on your house’s wiring. Damaged wiring can cause shorts in home electrical systems, thereby tripping breakers and causing lights to dim or go out for short periods.

6. Chewed Wires Caused a Fire Accident in Your Home

This is perhaps the most extreme sign of mice chewing on your wiring, but an unfortunate possibility. If mice chew through wires and leave exposed wires hanging around where flammable materials are, the wiring can very easily cause a fire. 

In severe cases, it may be difficult to pinpoint the culprit. A report in 2012 estimated up to 25% of fires with undetermined causes may be the result of rodents chewing on wiring.

It’s also worth considering that mice and rats can also chew through gas lines, which can be very disastrous as well.

7. There Are Signs of Mice Nests

Mice, like other rodents, love paper and cardboard. If you see shredded paper or cardboard in odd places around your home, inspect the corners you seldom visit for unwelcome mice nests. Rodents love to build their nests out of paper and cardboard and will always do so in a dark and secure place you rarely visit.

8. You See a Mouse Chewing on Your Wires

The most apparent sign a mouse is chewing your wires is if you directly see it – duh, right? This is less likely than the other signs on this list because mice are nocturnal creatures. They go to great lengths to only wander and forage when you aren’t around, like when you’re sleeping or not at home.

How To Prevent Mice From Chewing Your Wires

Seal Your Home

Use caulk to seal small openings in your home, especially in corners and crevices you usually wouldn’t think to check. If an opening is so large that you can’t completely seal it with caulk, try filling it with steel wool. Mice can chew through a lot of things , but steel wool isn’t one of them! 

Other essential things to seal off are areas where cables may lead outside because rodents can create larger holes and damage the cable in the process. You may wish to consider having the wiring behind your insulation checked to ensure mice haven’t been snacking on the insulation or wiring. If they have been, seal it up with caulk and steel wool as best as you can.

Ensure Trash and Food Are Put Away

A key factor in limiting any pest, from insects to rodents, is to cut off their food source. Immediately clean crumbs and wash dishes that have food debris or residue on them, and take special care to not leave paper or cardboard lying around – mice will eat those in a pinch too!

For indoor trash, take it out more frequently to avoid enticing pests. Locking trash lids can be extremely useful for indoor and outdoor trash cans, keeping intrepid rodents away from your trash. If there isn’t any food they can access, they’ll be more likely to leave your home alone and go elsewhere.

Get Wires Covered with Steel

There are plenty of ways to protect wires, but I’d recommend getting wires covered with steel or hard plastic – even mice can’t chew through them. Another method to protect wiring is to move low-lying cords off the ground where mice could chomp on them.

Trim Trees

If you have trees that could give enterprising rodents like mice or squirrels access to your roof, that’s a weak point in your home’s defense. Have any tree branches or other vegetation trimmed back so that it can’t give pests a chance to leap onto your home.

Final Thoughts

It can be irritating and disturbing to realize mice are chewing on your wires. Fortunately, there are multiple ways you can prevent them from chowing down on your delicate electrical cables in the future, such as sealing your home, securing your wires, putting out food or thrash away, and trimming trees.