As some history to this, I started the hobby in February, have five aquariums now. Breeding shrimp, guppies, and mystery snails. Two of the five aquariums show these eggs, but they have had no common input that I know of. Before I treat the tanks to kill unwanted species, I wanted to reach out to get opinions. If I had a microscope, I'd definitely look closer. I tried vacuuming, but they are as heavy as the substrate so I'm just burying them. If nobody has any ideas, I may pull the mystery snails and dose the tanks with "No Planaria." I understand it kills most unwanted guests... without harming fish or shrimp.