New RBTA - How do I get him to stick?

[levi1803]

I was lucky at first, put my RBTA in the tank and it moved about an inch and stayed there for the past 4 months, then about a week ago I moved the rock it was on about an inch and now the thing decided to wonder around all over the place, I finally moved the rock it was on (to close to a few other things) to the other side of the tank and so far it hasn't moved in two days, so I'm hoping it stays there.