Can roaches ruin electronics or appliances?

German cockroaches are thigmotactic — they're wired to seek out tight spaces where their bodies contact a surface on more than one side, and they strongly prefer warmth. A microwave's transformer, a router that never powers down, a refrigerator's compressor housing, and a game console under load are all small, dark, reliably warm voids, which makes them attractive real estate independent of any food source nearby.

This is also why the problem tends to show up in kitchens and entertainment centers before anywhere else in a house: those are the rooms with the highest concentration of always-on, heat-generating devices.

Once roaches establish themselves inside a housing, their droppings and shed skins accumulate on and around circuit boards and contacts. In a heavy, long-running infestation, that debris — combined with the mildly acidic nature of roach droppings — can corrode a contact or bridge a connection enough to cause a malfunction. That is a real, documented mechanism.

What isn't documented is how often it actually happens. No independent study tracks the rate at which infested devices fail versus simply host roaches without incident, and the trade sources that describe the mechanism don't quantify its frequency. The honest answer is that device failure is a plausible, occasional outcome of a heavy infestation — not something that happens to every appliance a roach walks through.

The peer-reviewed literature on cockroaches and health is far more solid than the literature on cockroaches and appliances. A landmark study published in the New England Journal of Medicine found that 36.8 percent of studied inner-city children were sensitized to cockroach allergen, and 50.2 percent of their bedrooms had high levels of it in the dust. Subsequent NIH-reviewed research has found cockroach allergen present in the large majority of studied inner-city homes and identified it as a significant, independent risk factor for asthma morbidity.

That's the part of the roach story with an actual number behind it — and it's a health story, not a property-damage one.

It's worth being precise about class of problem here. When roaches do disable a device, that's functional damage — a system stops working. It is not structural, and it is not the fire-risk story that belongs to rodents chewing wire insulation; roaches don't gnaw conductors, and nesting-related fouling is a different, much lower-consequence mechanism than an exposed, arcing wire.

So the honest read is: harborage is routine wherever roaches are established, device damage is occasional, and the health exposure from the allergen they leave behind is the risk most worth acting on regardless of whether a single appliance ever fails.