I have a horrifying story about my hermit crabs. Prepare yourself. I had two of them when I was a little kid, and I didn't know that they needed bigger shells as they grew. They both were too big for their shells, but had no bigger ones to move to. One of the crabs was big and had a soccer painted shell, the other smaller and with a red shell. One day I came home to find devestation- the bigger crab's shell was empty, the red shell had the bigger crab in it, dead, and the smaller crab was lying in the sand without a shell, dead. What had happened was the big crab had been so desperate to escape his shell that he saw the red shell, and without realizing it was even smaller, killed and removed the smaller crab. Then, he stole the red shell and suffocated to death in its small confines that left him even less room to breath. All these years later I still feel terrible about this murder-suicide of my poor crabs.