It’s really gross to think about. I mean you’re sitting there watching TV and there could be bugs munching on your cables in the attic or in the walls. Or is it just a myth?
Unfortunately it’s not a myth. There are several breeds of pests that are attracted to the rubber insulation in your cables. Termites and silverfish both seem to find cables quite interesting and though they’re not likely to bite, if they do they could start nibbling into you picture quality.
It doesn’t seem like a tiny insect bite would be an issue, unless of course they really chow down. Sometimes they do, and sometimes the real issue is formic acid. Formic acid is a naturally occurring chemical secreted by termites and ants. It’s used in their digestive process. It’s not a particularly strong acid, but it can dissolve rubber insulation over time. Once the rubber jacket is exposed to air, the cable inside can begin to oxidize and boom, there goes your reception.
As with all bug infestations, the best thing to do is try to avoid them from the start. If you run a lot wires through the walls or in the attic, you should tell the exterminator but most modern chemicals are safe for use on cables anyway. If you do think you have a bug problem, the best thing to do is to start with professional treatment. You may want to get up in the attic (which could be kind of gross at this point) and take a look to see if there’s been any damage to the cables you have. Don’t just spot check because insect bites can be fairly small.
Hopefully, this is something you’ll never have to deal with, but you should know that there’s a limited lifespan for cables, they do eventually oxidize and you should always be thinking about how old that wiring is (especially for TV and high-speed data) and when you should plan to replace it.