What are these and should I be worried about them??

These little things are popping up in my reef, and I have no idea what they are, but I need to know if I should be worried about them, and how to get rid of them if they are something to be worried about...they are flat, oval-ish, and don't appear to move much..but do move (i'm guessing more at night?)...it really hard to get a good pic of them, even with my good camera...but here is the best i can do...I circled the little "things" in red :-/:-/

 

one more pic

 

Nerite snail eggs.

 

They look like eggs, at least in the third & fourth pic in your first post.

 

Ok I just did add a boat load of nerite snails to my tank from reef cleaners about 3 weeks agao....that probably explains it...and when i dont see them where they used to be, i assume that means they hatched or someone had an omelet..lol..::whew:: i was worried that they were flatworms

 

Bad thing about them is that 95% at least are just capsules and never hatch. My rocks, pumps, other snails are getting pretty well covered with white disks.