I had a ferret do this, and he never stopped. He always had to be watched when in the cage and during playtime. Many boxers and pajama pants were turned "holey" before we found out. He pooped out the fabric, but it took a long time before all of it came out. Odder still, it was almost "bleached" and became brittle and feathery sometimes, from the digestion so sometimes it didn't seem like fabric but we knew it was. Sometimes they do it because they're bored, and this ferret had run of the house; he had no medical problems or ulcers. All I can say is don't give the ferret an opportunity...I hope someone else has more info. Laryssa [Posted in FML 5841]