You missed the point. I’m not worried about a cat getting electrocuted by chewing on the wire. I’m worried about depending on the wire to power the device that feeds the cats. If they chew through the wire and the unit ceases to function, I may end up with a dead cat or two. Batteries are a more reliable solution in this case. If the batteries last up to 6 months, putting a fresh set of batteries in the device before going on vacation eliminates lack of power (such as dead batteries or cats chewing through the wire) as a failure mode.