Teardrop Max Question - Hydroids

[Instar]

My teardrop from Nam came with hydroids. It is covered about 90% in these little fuzzy brown hydroids.
Do they pack enough punch to cause damage to the clam mantel?
Should I scrub them off? If so, what will really remove it down to the rhizoids?
If there is no real reason to scrub them off, then you know me. I think they're cool. :)
The bottom line - is action required on my part here?

[OrionN]

One of my teardrops also have Hydroids on it. This particular Clam attached himself, of all place, to the front glass of the aquarium so I cannot tank him out of the aquarium. I have never have Hydroids in my tank before. I read that they can sting other animal but my slam seem unaffected by it. I also read taht they require very high light to live. Lower the light level and they will die out.
I plan to leave my be unless I can see some problem. I would keep you clam away from the rock structure so that if there is any problem, you can take him out and clean him.

[Instar]

Once I took him off the shelf, he attached right away to the small cluster of rocks I put him on. He has not even tried to move from there. Those small rocks come out very easy if some action is needed. I got a picture of this clam at just the perfect angle, looking down into the intake siphon. Wow, I never knew they were that colorful inside!

I've had these kinds of hydroids in small clusters here and there on live rock. They usually cycled or died off or got eaten. Never had this many of them before in one place. I never saw them sting anything like I have seen the little white ones sting and annoy things near them. Snails eventually eat the white ones when they get a little algae on them. Not these though. Limited experience with these brown ones.

[Instar]

Minh,
Zhenya provide a couple links and if you follow the threads there is a lot of info about hydroids and predators of hydroids.
General recommendation by zhenya and shimek is to scrub them off, get them out of the tank due to the reproductive capacity of this kind of hydroid. At the moment, my carnivorous bicolored blenny is eating them. I knew he had to be good for something besides eating coral.
Here's the link to the thread on clamsdirect.com to all the info on reefcentral:
http://www.clamsdirect.com/phpbb2/viewtopic.php?p=4039#4039