I've had rodent damage to the fittings themselves - chew marks but not all the way through.
Never had any rodents chew through the pipe itself though, either speedfit barrier stuff, or the blue mdpe, and I've got miles of that through high-rodent areas.
I have a theory it's too soft for rodents to use for teeth sharpening, or it tastes nasty or something. In the same stretch I've had electric wires eaten to the conductors.
Wondering what others' experiences are?
