Ok so I know how hard this maybe to answer but a picture is VERY hard to get with these things. On my glass I am finding many small flat white sacks I guess with a yellow "thing" in the center.

They just started appearing and in some areas there are many of them... say 20 or so. They seem to be flat and are the size of a click pens head with something yellow in it. What are these?

All that is in my tank are snails, hermit crabs, 2 Damsels, and 7 mushrooms.