Anyone know why a gerbil would eat his own back legs and tail? I thought he was being attacked when his first leg was injured and removed the gerbil that I thought was attacking him. Last night, my daughter saw him eating his other leg and now I see his tail has been bitten. He is with his brother, but I have never seen them fight. They cuddle with each other all the time. What's going on? This is horrifying. Thanks for reading.