Do cockroaches damage anything besides food?

UC IPM, a leading university extension source, states directly that cockroaches "destroy fabric and paper products, and impart stains and unpleasant odors to surfaces they contact." That's a real and well-documented mechanism: cockroaches graze the starchy sizing and glue in book bindings, starched fabric, and wallpaper paste in much the same way silverfish do, and their droppings and regurgitation leave dark staining and musty odor wherever they travel repeatedly.

That staining and grazing is genuine cosmetic damage — annoying, sometimes stubborn, but never structural. It's the honest, sourced part of this question, and it deserves to be said plainly without either inflating it or dismissing it.

The specific claim that cockroaches chew through wiring and cause electrical fires does not hold up. Cockroaches have no chewing adaptation aimed at insulation, and more fundamentally, wire insulation has no nutritional value to a roach the way it does — through obligate incisor wear — to a rodent. The U.S. Fire Administration's residential electrical-fire data attributes ignition to wiring and electrical-distribution faults, and no fire authority names cockroaches as a contributing factor anywhere in that data.

This is worth being direct about because it's the biggest gap on this page: a claimed severity around 70 against an evidence-supported severity closer to 30 is a wildly overstated hype delta, and the fire framing specifically is what's driving that gap, not the staining and paper-feeding facts, which are genuinely well documented.

There is a real, if narrower, electronics angle worth naming honestly. In a severe, long-ignored infestation, accumulated droppings, shed skins, and body debris can bridge or foul electrical contacts, occasionally contributing to a device malfunction. That's a mechanism grounded in fouling and debris buildup, not gnawing, and it requires a genuinely heavy population sustained over time — it is the exception, not something that happens with an ordinary kitchen roach sighting.

The genuinely well-documented health risk hiding behind this question isn't fire — it's allergen. Cockroach allergen, specifically Bla g 1 and Bla g 2, is rigorously documented in the medical literature as a leading asthma trigger, with a landmark New England Journal of Medicine study linking exposure to asthma morbidity in inner-city children specifically. That risk accumulates in household dust wherever a cockroach population is active, and it's the health concern worth acting on — not a fire risk the evidence doesn't support.