Rodent Damage to Electrical Equipment: Coordinating the Response

Gnawed insulation on a cable tray, droppings beside a control panel, or a machine that trips out and turns out to have chewed wiring inside. Rodent damage to electrical equipment gives a commercial site two jobs at once: making the equipment safe, and finding out why rodents were there in the first place.

Those jobs belong to different specialists. A qualified electrician deals with the damaged wiring and equipment, and a pest control provider investigates the activity, the routes, and the control and proofing needed. Instant Pest Solutions handles the pest side only; we don’t carry out electrical work, inspection, or testing. This guide is for facilities, operations, and site managers who need both jobs done in the right order, with nothing falling between them.

Safety first, then the investigation

If there’s smoke, a burning smell, sparking, or any sign of fire, follow your site’s emergency procedure straight away. That’s not a pest control call, and it shouldn’t wait for one.

In every other case, the first steps are simple. Keep people clear of the damaged equipment, stop it being used through your site’s normal fault-reporting process, and call a qualified electrician. Isolation should be carried out by someone competent and authorised to do it. Nobody should open a panel, move a cable, or wrap tape around a damaged section to make it look safe, and nobody should reach in to get a better photograph.

The HSE’s guidance on electrically powered equipment says equipment should be taken out of use if its safety is in doubt and checked by a competent person. A machine that still runs isn’t proof that its wiring is sound, so the decision to put it back into service belongs with the electrician.

Two jobs, two specialists

It helps to write down who is doing what. The electrician assesses the damaged equipment or installation, carries out any repairs, and tells you what can and can’t be used. Our team investigates which pest is involved, how much activity there is, how it’s getting in, and what control, proofing, and monitoring are needed. The business decides how operations continue within the limits the electrician sets.

Give the incident one site coordinator. They don’t need to make specialist decisions; their job is to arrange access, pass information between contractors, and make sure the next shift knows what’s out of use. For leased machinery or specialist controls, bring in the equipment owner or maintenance provider early, as they may need to be involved before anything is opened or replaced.

Be clear about the order of work too. The pest survey can usually go ahead around a restricted area while the electrical work is arranged, but some spaces, such as an electrical cupboard or riser, may need to be made safe before anyone else goes in. The HSE’s guidance on using contractors stresses sharing information about the work and its risks, so a short joint briefing between the electrician and the pest technician is worth the time.

What to record from a safe position

A useful first report is short: the building and room, the equipment reference, what was seen, when it was found, and who has been told. Photographs taken from where you’re standing are fine. Getting closer to improve them is not.

Describe what you actually saw. “Chewed outer sheath on the cable tray above bay 4, droppings on the floor beneath” is more useful than “rats in the electrics”. An electrician may find a different cause for a fault, and our survey may find the main activity somewhere else entirely.

Note any recent changes nearby: stock moved closer to a plant room, a disused area brought back into use, or a contractor opening up a service route. These details help direct the investigation, even though they don’t prove what caused the problem.

How the pest side is investigated

Rodents gnaw constantly to keep their teeth worn down, and cables in quiet, warm spaces are easy targets. Rats and mice are the usual suspects on commercial sites, but grey squirrels cause similar damage in roof voids, and squirrel activity falls under our wildlife control service rather than rodent control.

The spot where a cable was damaged is often a feeding or travel point rather than the way in. Our commercial rodent control service looks at the wider pattern: droppings, rub marks, runs, nesting material, and gaps around service penetrations, cable entries, and doors. Existing monitoring records help, especially if they show activity near the same area or note places that couldn’t be checked.

Tell us about access restrictions before the visit, including any equipment that has been isolated, areas that need an escort, and times when the space is in use. That way the survey covers what it can safely, and any gaps are recorded as gaps rather than assumed to be clear.

Control and proofing around live services

Control measures near electrical equipment need planning. Your team shouldn’t put down their own bait or traps in response, especially not rodenticides. Professional use of rodenticides in the UK follows the CRRU stewardship regime, which our article on CRRU rodenticide stewardship explains, and the choice of method depends on the site and what’s being protected.

Proofing is where the pest and building work meet. A gap around a cable entry may need closing, but the closure has to suit its location and can’t compromise ventilation, maintenance access, or fire stopping. We’ll set out what needs proofing and why, then agree the sequence with you and, where it affects electrical routes, with your electrician. Staff shouldn’t stuff wire wool or foam around cables themselves.

When rodents have been living in a roof void or ceiling space for some time, contamination can be as big a job as the damage. Our guide to loft clearance and sanitisation after rodents covers what that involves.

Keeping the site running meanwhile

A specific equipment list is easier to manage than a general warning that the warehouse is affected. Identify each item that’s out of use, what depends on it, and any alternative the electrician has confirmed is safe to use. A conveyor, a chiller, and an office network switch have very different consequences, even if the damage was found on the same walk-round.

Don’t improvise with extension leads, move machinery, or reconnect circuits to recover lost time. Tell the electrician what the business needs to keep operating so they can advise on safe options. Food businesses should also involve their food safety lead where refrigeration is affected or food may have been contaminated.

Make the restrictions visible to supervisors, cleaners, and contractors who arrive out of hours. A clear note saying which equipment is out of use, and who can authorise a change, is far better than a verbal message that the electrician has been.

Closing both jobs properly

When the electrical work is complete, record the outcome and any remaining restrictions. Then review the pest action plan alongside it. Repaired wiring, outstanding proofing, unresolved access, and the next pest visit are separate items, and one completion email shouldn’t close them all.

A quiet monitoring period doesn’t authorise damaged equipment to restart, and a completed repair doesn’t mean the rodent activity has stopped. If fresh signs appear near repaired equipment, report the exact location and time. It deserves another look, but it doesn’t automatically mean the repair has failed.

Questions about rodent damage to equipment

The machine still works. Can we keep using it?

Not until a qualified electrician has checked it. Damaged insulation can expose live conductors without affecting how the equipment runs, so normal operation tells you nothing about its safety. Take it out of use and keep people away until you’ve had the electrician’s advice.

Does a recent electrical test mean the equipment is safe?

No. A test or inspection records the condition at that time. Damage found since then needs reporting and checking on its own merits, and a dated label shouldn’t override a current concern. Fixed wiring and portable equipment are also assessed differently, so ask your electrician what the damage affects.

Can our staff clean up droppings around the equipment?

Not on or inside electrical equipment until it has been made safe by a competent person. For surrounding areas, follow your site’s procedures for handling rodent contamination, including the right protective equipment and an assessment under COSHH. Where contamination is heavy or widespread, ask us about specialist clearance.

Does it matter whether it’s rats, mice, or squirrels?

Yes. The species affects where to look for the route in, which control methods are appropriate, and what proofing is needed. Squirrels in a roof void, for example, are handled differently from mice in a ground-floor comms room. Our survey identifies the species before recommending control.

Should we keep damaged cables or components?

Ask your electrician and, if relevant, your insurer before anything is thrown away. Record safe photographs and equipment references through your agreed process. Staff shouldn’t keep exposed or contaminated parts in an office drawer.

Is rodent damage to wiring covered by insurance?

That depends on your policy and the circumstances, so check with your insurer or broker and follow their reporting requirements without delaying the safety response. Keep factual records of what was found and what work was done, from both the electrician and the pest survey.