Clam won't stay put!

[pelle31]

My Clams used to move around as well. Had them on the sand,on Rocks,both sides of the tank and the middle. I have now put them on the right side of the tank and they pretty much stay put. I have 2 larger ones and one little guy,the 2 larger ones stay put and the little one moves back and forth between the two,its actually kinda comical. The thing that kinda sucked was when he attached to the side of one,good thing he let go and went looking for the second one. I just moved them around untill they stopped moving,dunno if that helps you or not but thats what I did.