Brought home a nice RBTA a few days ago. Seemed to be doing well---it moved around a bit which I understand is expected. I saw it this morning and now...it's nowhere to be found. I even felt around the back of the rocks and ledges...nothing. Is this common for them to completely "disappear" for a while?? I'm hoping it's just found a niche somewhere but I'm concerned that it can't be located. I've been told that they move around some while they're finding their "home" in the tank. Should I just wait for it to show back up or should I do a little more hunting?? Thanks for any help.