Last night my son noticed casper's empty shell floating in the second level of the water fountain. This troubled me a little because there were no shells up there for him to have switched into, and I can't imagine that he would have carried it back up there after a shell change. I have no idea how it could have gotten there. I've been keeping my eye out, and I have yet to see him- although it isn't unusual for him to stay buried most of the day. Only after trying to figure out how the shell would have gotten there I realized that it may be possible that in an attempt to squeeze through the small opening in the top of the tank where the cord for the fountain is, is it possible that he shead his shell to fit out? Could he be streaking in my house somewhere? And if so where do I look? I searched along all of the walls & baseboards & I've turned off my AC to keep the temp/humidity at a level he could survive in. Has anyone ever heard of this happening? Am I worrying for nothing? What are the chances that a crab would do something like this?