You're not going to believe this, but apparently I have had a mantis shrimp living in Thomas' 30 gallon tall Eclipse along with Thomas almost the entire time I've had him (we're talking almost a year now). This is amazing, because I can't tell you how often I've put my hand in there, to clean the glass, to shoot pesky aiptasia with Joe's Juice, to play with Thomas, etc. Last night, I was watching a bunch of copepods crawling around the live rock and thinking to myself "almost killed all the aiptasia, just need to keep it up, every day, see any of them, hit them with Joe's Juice, bye bye anemone" - when I see these 2 beady little eye stalks staring out at me, right at the front of the tank out of a piece of live rock! My first thought, "What the ****!?!? That looks like a MANTIS SHRIMP?!?!" "No way", I say to myself, "It CAN'T BE! I haven't added any new live rock to the tank since a couple months after I got Thomas!" (back in May '05). I take a closer look, and this "thing" ducks back into the rock slightly, but I can still see the eyes and the unmistakable mantis-like movements. In complete shock, I head to the freezer, tear off a small piece of shrimp and put it on a feeding stick to see. I get back to the tank, and slowly ease the stick down towards the Mantis. As the feeder stick gets close, "it" shows no interest and *BOOM* quicker then I've seen anything move in a long time it darts out of the whole and under another piece of live rock! I had heard strange clicking noises from Thomas' aquarium every so often in the past, but thought it was just a piece of equipment "ticking" or Thomas doing something. Apparently it was the Mantis digging a new hole or beating a helpless hermit crab to a pulp (I think it's a smasher, not a spearer, which I also believe are "slightly" less aggressive). I still have only seen him once this entire time. I can't find him since, but I can hear him more now. Also, Thomas is getting older now, his color has been a consistant whitish-grey the last 2 months instead of the normal brown. Thoughts? Comments? Suggestions?