We started his love of destroying cardboard tubes early on and this is a love that has stayed with him. (In fact, we have several bags of the things lying around and he gets to tear up one or two every day or so). He doesn't eat the cardboard, though. These things were made purely for the shredding into itty bitty pieces and distributing to the four corners of the apartment, so Mom's weekly cleaning job is made that much more difficult.
But he is worth it. :)