migrating polyps


So is it normal that tons of my polyps are cruising around the tank? I rearranged my rocks about a month or so ago, and since then they have been moving like crazy. I have one that even cruises the glass....this is strange right? I put a new rock in and it seems like a lot of them want to be on that one little rock. Is this a sign that they are unhappy with the new arrangement? Or is it normal?
Tanks guys!