[I got a small zoo rock back about a month ago. I didn't notice until after a few days of being in the take that the rock had these little brown rectangular spots with one end of it looked to be flapping in the water movment. Since then they have spread all over the tank as well as there is a lot more on that same rock... what are these suckers and how do I go about getting rid of? From all the searching I have done I can not seen to id them. Please help!]