Tube worms???

[Porkibear]

I've noticed that my tank has now been slowly developing more and more of these tube-like growths on liverock as well as soft coral frags near the base. These tubes are small, and have a small base attached at the bottom of each. They don't look like they do much, but it seems that whenever I do a water change, or use my turkey baster to clean off the liverock, these tubes emit a slimy string of mucus. It almost looks like spiderwebs in the water.

They seem to be overpopulating...is there a natural predator against these things?

[Paintbug]

they are called Vermetid Snails. they can over run a tank. they dont directly cause harm, but sometimes they may cause some irritation to a coral. they can also become an eyesore for a display tank. the only effective predator i have found is me, and my fingers plucking them from the rock. heres alittle info:
http://www.reefkeeping.com/issues/2005-01/rs/index.php
http://www.reefs.org/library/aquarium_net/0897/0897_8.html