[unclejed]

Hey ross, I see my crabs doing things like that. They kind of have a pecking order and if one wants another's shell it will pull the other out and then the one pulled out needs a shell quick! Yours is funny in that they just exchanged. Sometimes the one will kill the other to get his shell. Make sure you but some different size shells from lfs (empty) and put them in your tank. As they grow they need bigger shells to house them.