egg sacs

Hey guys i’ve been seeing those egg sort of things on the side of my glass with small white balls in them. They keep coming back everytime i remove them. Any idea what it is ?

So my two pro escape artist nerite snails decided to lay eggs about two weeks ago...all over my tank. Literally on the rocks, the pumps, even on my beloved turbo snail, Vagine. Most of the egg sacs on the glass have been developing it seems. I say this because when they were first layed they...