I used to have this problem. They were in my fluval, sump, skimmer, everywhere! They didn't hurt anything though and I love looking for them lol. I took my tank down for a year so no more! :'(
I wish I knew somebody around here with good live rock! All I have right now are tigger pods everywhere and I found a dead rock crab on some live rock from the Lfs. No good rock at any stores around here!