Squirrels and woodpeckers both raise hell on both power and telephone networks, I've seen both dig into and eat lead covered telephone cable as well as make a pole unsafe due to making nests in them like they do in trees
I had one squirrel scare the holy beholy out of me while I was on a pole belted off and working and that little turd came hauling down the opposite of the pole until it got to my safety belt and climbed around it towards me and stopped, I whack him off my belt with my bare hand before thinking Scare me bad
He landed in a tree and ran off making all kinds of chirping and squealing noises, better him than me