I agree totally with Jaysmonkey.
Many buns do nibble through live cables & are apparently unharmed.
I suspect it's because they do not sweat, & have thick fur on their feet, which acts as an insulator. If your bun has a wet foot for whatever reason, you may not be so lucky next time.
It's everything protected & off at the plug in this house, + bun out of the room when I'm hoovering!
ETA mine has only chewed the 'phone & internet cables when on, & in use to "detach me" from giving the wall too much attention!