can someone help me ID these snails?

about a month ago we noticed a couple of these little snails showing up on the glass of our tank, now they got a bit bigger and they are all over the place. There must be about 50 of them at least , i have no idea what kind of snails they are, if they are harmful to the tank, or if they are just spawning machines. We did notice eggs at one point however there aren't any at the moment. (ill take pictures if they show up again )

 

I think I am to much of a newbie to be giving advice, but I think I seen them before, not sure what their called, but I do think you may want to get rid of them, like the fresh water version of the garbage snail, you will have 100's of em, but I would wait for better advice

 

thank you

 

Ceriths I believe.

If I'm right they are good to have.

 

This looks like a job for http://www.3reef.com/forums/members/pagojoe.html

 

I found that this snail if it is the Cerith Snail is extremely difficult to breed in captivity and are larger at breeding size, if their populating like crazy in your tank, chances are best it ain't the Cerith.

 

Yup, they're ceriths.