A common question from Lubbock homeowners dealing with rat activity is what the animals are actually capable of damaging. The short answer: rats can chew through more than most people expect, and the most serious risks — electrical wiring and PVC plumbing — are the ones homeowners are least likely to discover on their own. This guide covers what rats can and can't chew through, and what the risks are.
What rats can chew through.
Soft wood and drywall.
Pine, cedar, and most framing lumber are easy chewing material for rats. Drywall is similarly soft. Rats chew through both primarily to enlarge access gaps — an existing 1/2-inch gap in drywall becomes a 2-inch opening after a few nights of gnawing. In Lubbock homes, we most commonly find gnaw marks at the base of interior walls (where wall meets floor framing), at cabinet toe-kicks, and at the garage-to-interior-space doorframe base.
Plastic and PVC pipe.
Roof rats and Norway rats can both chew through thin-wall PVC and ABS plastic pipe. Drain pipe and conduit are common targets. A gnawed PVC drain pipe under a bathroom or kitchen can leak slowly inside the wall, and may not be discovered until water damage appears at the surface. Thin-wall electrical conduit is similarly vulnerable.
Electrical wiring insulation.
This is the most serious chewing risk from rats in Lubbock homes. Rats gnaw on wire insulation as a dental behavior — they don't consume it, but they wear down their incisors on the insulation surface. A wire with chewed insulation has exposed copper conductor that can arc against adjacent metal or ignite insulation material in contact with it. The Consumer Product Safety Commission identifies rodent wire chewing as a contributing factor in a documented percentage of residential electrical fires. In Lubbock, we flag every instance of wire chewing found during attic inspections and recommend an electrician assessment. The older homes in Tech Terrace, Overton, and Dunbar Manhattan Heights — where multi-season attic infestations are more common — have the highest rate of wire chewing we find.
Aluminum sheet metal.
Thin aluminum can be chewed through, though it takes more effort than wood or plastic. Heavier-gauge galvanized sheet metal and hardware cloth are practically unchewable for rats — which is why they're the recommended exclusion materials rather than aluminum flashing or thin metal.
What rats cannot chew through.
Rats cannot chew through: cast iron or steel pipe, concrete (though they can exploit existing cracks), glass, and properly installed hardware cloth or sheet metal with a gauge of 24 or heavier. This is why hardware cloth is the standard for exclusion sealing — it closes the gap physically without the rat being able to re-open it by chewing.
The fire risk from wire chewing.
Wire chewing by rats is the damage type we take most seriously in attic inspections. Unlike structural gnawing, which is visible and can be assessed, wire damage in an attic often isn't visible from below and may not produce any immediate symptom until a connection failure or arc event occurs. If your property has had a confirmed roof-rat attic infestation — especially a multi-season infestation in an older Lubbock home — an electrician inspection of the attic wiring is a reasonable precaution even if no specific damage has been identified. We note wire chewing in every inspection report we produce.
If you find gnaw marks on wiring during any inspection, treat it as a priority: call an electrician before relying on the circuit for normal use. See our attic cleanup service for how we document damage found during post-infestation inspections.