Batteries good for people and rodents
The other day a rat ate the wiring in a Chevy Volt left in a parking garage overnight, causing $600 worth of damage according to Cars.com. Apparently, because of the frigid Chicago temperatures, the rat was drawn to the warm battery in the Volt, which maintains a minimum battery temperature even when the battery is fully charged.
Obviously, this can and has happened to non-plug-ins as well, but plug-ins could be particularly intriguing targets for rats because of minimum battery temperatures.