Hey- Check this out!! Printing 3-D Shells for pet hermit crabs! I'm not sure about what they're made out of, etc, but if they can make shells on a 3-D printer that are safe for crabs, coolio!! Take a quick look. http://www.makerbot.com/blog/2011/10/27/everyones-talking-about-project-shellter/ Vicki- maybe you could carry them in your store or something if they become available and are safe!!