Pyramid snails!!! big problem!

[KErickson978]

While cleaning my tank i noticed one pyramid snail on the shell of my larger crocea clam, so i went to pick it off and noticed that its byssal threads were pretty much gone so i picked it up and found about 15 more of the little bas&^#$@ on the shell. at this point i am freakin out because i just added another crocea no more than 4 days ago, and dont want both of them to be attacked much less one of them. should i set up a temporary quarantine tank for the clams? i dont have any idea of how to get rid of these creatures or how bad they actually are.. the snails i found have been removed and disposed of... i took some pictures but wont be able to post them tonight cause i need to put them on my other computer then transfer them to a memory card that fits this one but the memory card is nowhere to be found =(
i dont know if it not having been connected to the rock is a sign of problems or not but to me its bad cause its been attached to that spot for about 5 months constantly.
Any and all help is greatly apreciated!!!!!