Yes, and this is the part of the subject that deserves to be taken seriously rather than filed under nuisance.
Everything else a squirrel does in a roof space is a repair bill. Gnawed cable is a fire risk, and it is the reason a loft problem is not something to leave until the spring.
Why cable specifically
Not out of malice or hunger. Squirrel incisors grow continuously and have to be worn down, so the animal gnaws daily on whatever has the right resistance. PVC cable sheathing happens to be close to ideal — firm enough to be worth working on, soft enough to give way. It also runs conveniently along joists at exactly the height an animal moves at.
Modern lofts make this worse rather than better. Rewiring, extra circuits, downlighter cabling, alarm and network runs, solar and boiler controls: there is far more cable in a roof space than there was fifty years ago, and much of it is clipped along the top of the joists in the open.
What damaged cable does
- Exposed conductors, which can arc against each other or against anything metal
- Arcing in insulation, which is a fire in loose mineral wool and dry timber
- Nuisance tripping, as an RCD detects the fault intermittently
- Circuits failing, often one lighting circuit at a time
- Faults that are hard to trace later, because the damage is buried under insulation
Act on these today, not after the pest work: a smell of burning or hot plastic, scorch marks, a circuit that trips and re-trips, flickering lights, or sockets and lights that have stopped working. Switch that circuit off at the consumer unit and call a qualified electrician.
How to check without going into the loft
From the hatch with a torch, look along the tops of the joists near the hatch itself and towards the eaves. Cable is usually clipped there and is visible without going in. What you are looking for is bright copper, white inner sheathing showing through grey outer, or a cable that looks chewed rather than cut.
Photograph anything you find rather than touching it, and treat any cable as live.
Getting it put right
The pest work and the electrical work are separate trades and both are needed. Deal with the activity, close the roof, and have an electrician inspect and repair anything that has been gnawed. Where there has been sustained activity near cable runs, an inspection is worth it even if nothing is obviously damaged, because the parts you can see from the hatch are the minority.
It is also worth checking an insurance policy rather than assuming. Damage caused by vermin is commonly excluded, and where it is covered an insurer will usually want to see that the problem was addressed promptly.
Questions
Do they actually cause house fires?
Damaged cable in a loft full of insulation and dry timber is a recognised fire risk, which is why any electrical symptom is treated as urgent rather than waiting on the pest work.
Can the cable just be taped up?
No. It is an electrician's repair, and the affected section normally needs replacing rather than patching.
Should I turn the power off to the whole house?
Isolate the affected circuit if you can identify it. If there is a smell of burning and you cannot, switch off at the main switch and call an electrician.
Squirrel Control Costs
Squirrel control is £280 fixed cost. Proofing work, where it is needed afterwards, is £180. Call 01502 630 122 and tell us what you have heard or seen.
To arrange squirrel control, call 01502 630 122, or read the squirrel control page.