1 more hitchiker to add to the fun!

I was watching my tank the other day and noticed that one of my rocks had legs.  They were deffinately crab legs.  I saw no sign of a shell so I knew it wasn't a hermit.  Then about 2 days ago the power went out and the tank went compeletely black, so I took my flashlight to see if all was doing well, and there it was.  A little itty bitty stone crab not even a cm. across was sitting outside the hole that the legs were in.  I'm not too worryed about him now.  I'm sure all he's after is pods for the moment, but little things tend to get big.  Does anyone have any success storys for removing him?  The food in the jar didn't seem to work, so I'm out of ideas.