I got him a week ago and placed him on on some little rocks with crevices .... The rocks with crevices were on top of a flat rock with only one whole in it . ... He didn't move too much , but after a day or two , he moved a little . A foot at the most ... he moved underneath my powerhead . Then I placed a rock below him and he immediately moved down to the rock , but did not attach . Now he's right back where he started , but on the glass