Also known as land hermit crabs. Saw them at the pet store for the first time and they were fascinating and only $10. 4 or 5 of them probably as big as a tennis ball with shell and very active. picture link Didn't want to steal their photo so here's a link. Would've bought on the spot if I knew anything about hermit crabs. Just did a little research and it turns out hermit crabs can't be bred in captivity.