Baby snails harmful?

[ajreefer721]

A couple of weeks ago I found these small baby snails (at least that's what it looks like to me) and I'm not sure if they are harmful or not? For a while now most of not all of my Zoas have been closed up like you'll see in the first pic. I have a mix of sps Lps and softies. But only my Zoas look to be suffering from something and I'm starting to think these snails are the cause.
If there is anyone out there that has experience with these please help. Sorry for the crappy iPhone pics
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[pagojoe]

no, they're good guys.

 

[Sugar Magnolia]

Yep, those are collonista snails. That's as big as they get. Great little nocturnal scavengers.