noticed the other night a very small thing coming out of a hole in the rock, when i put a light on it in it goes, i tried to slowly get a little light on it and it turn out to be a crab.every night it seems to venture out a little more, will try to get a pic of it, very color full brown claws, with white tips, brownish black and white legs, the eyes are white with a red swirl,body is brownish, with little spikes all over his claw arms, but very small, had to get a magnifying glass to get a good look,seems to be picking at the rocks to eat, did something odd, was watching him he looked like he was blowing out his mouth you could see little particles flying all over, one other thing noticing in my tank at night will see these string like things flowing in the current, as soon as i put a light on them they retract back in, probably a inch or two long, anyone have any ideas on that,