Bad critters?

[Neil]

well, i have what looked to me like crushed leaves (however i know that they were not infact crushed leaves) in my tank. Upon closer inspection tonight i saw that these things are actually alive and moving about. Was wondering if they are some kind of flat worm or something? Searched around in the help section and couldnt find anything that nailed it down. They are on my glass primarily in the corners of my tank and as well on some of my LR. Suggestions to getting rid of them as well?