Hello! I have a pair of little sebae clowns in my 45. They are truly a pair of goofs. I bought about 50 lbs of liverock for them, and set it up in the tank with lots of caves and things. I got up the next day and found a large divet in the sand in the corner of the tank, that went all the way to the bottom right at the corner. I was confused, what did I have that would do that......my sea urchin?! Nope, I turned the lights in the room on after the tank lights had gone off, and saw my two clownfish huddled together in the divet, they looked VERY cute. I just thought that this might be an entertaining story, but was also wondering if I should be concerned, they have been doing this for over a month now?