Why Squirrels Chew Electrical Wires and How to Stop Them

It sounds like an urban legend, but it's a frightening fact: squirrels and other rodents are estimated to cause up to 20% of "undetermined" house fires in the United States by chewing through electrical wiring.

Why Do They Do It?

Squirrels aren't trying to burn your house down maliciously. They chew for two main reasons:

1. Teeth Maintenance: Like all rodents, a squirrel's front teeth never stop growing. They must gnaw on hard objects to file them down. If they don't, their teeth would grow into their jaws/brains, killing them.
2. Obstacles: Wires often run through holes in framing. If a squirrel wants to get through that hole to nest, they will chew right through the wire blocking their path.

The Danger Zone

When a squirrel chews the protective plastic insulation off a wire, it exposes the bare copper conductor. This creates two major risks:

• Arcing: If the bare wire touches wood, insulation, or another wire, it can spark (arc), igniting surrounding flammable materials.
• Short Circuits: This can cause breakers to trip repeatedly or outlets to stop working mysteriously.

Signs of Chewed Wires

• Flickering lights
• Outlets that stop working intermittently
• A burning plastic smell in the attic or walls
• Hearing scratching or scurrying noises in ceilings or walls