Came home to a strange sight last night. One of my sphods was eating one of her own arms! She is well fed, and actually is quite plump. She was holding the arm with her other arm, and just chomping away casually. Last I saw her, she had no injury, and I suspect she didn't recieve one after that unless she took a massive fall. But I doubt it. She ate it all the way down to first elbow. She left her other arm alone. I've never had this happen in my years of mantid keeping. Here's a pic: