I've had the same big piece of driftwood in Tango's tank since forever. It has holes all over it but I had no idea how deep they were or that they were connected.
I was sitting here at my computer and I saw Tango totally disappear into one hole on the side of it that's about the size of a ping pong ball. Just his tail tip was hanging out. I had a heart attack. I thought he was stuck. I jumped up to look and there's another hole in the front about the size of a nickle or maybe a quarter. I could see his head in it and he saw me and swam OUT that hole, looking all proud of himself. Darn daredevil. My hands were shaking and I swear he was grinning.
All this time I've been wondering how he keeps tearing his tail. I think I just figured it out.