Cardboard toys are the cheapest and most successful boredom breaker! Just take a care where you get it from obviously, and avoid those waxed cardboard grocery boxes. No probs if he eats it….if a bun is eating it excessively, it is likely craving the fiber and may need more hay in it’s diet, but for that occasional consumption, I don’t think you need worry. Chewing in general is good because it keeps the teeth in check. If you really want to give his teeth a workout, get him some aged apple wood or willow to chew on – and of course hay!

The cardboard is fine, especially plain, unmarked cardboard. (TP and paper towel rolls are excellent.) But since he’s a chewer, I’d move on to chew toys as jersey suggested. My thought is getting some unpeeled willow balls, maybe a willow basket, or one of the Timothy Hay Hidey things by Oxbow. Also, you can get some willow or seagrass mattes that he can tear up and chew. It’s like hay that’s been woven into something. Good for teeth and digestion.