We have two clowns that both seem to happily co-habit the same anemone. One is definitely more "in charge" than the other, but they don't seem overly aggressive to each other, certainly not to the point of causing any damage.
This has happened to me several times. Well, not me, personally - my shell is still attached!
Anyone know how quickly/frequently hermit crabs reproduce? I'd be worried of running out of shells for them all.