About a month ago I set up a 6 and a 3 gallon nano tank with neons and a couple of corys and baby plecos. (I have 60 tanks in my basement and this was a way to be "allowed" to set up a couple more tanks in the house) About two weeks after I set them up these little tiny clearish whitish "things started to appear on the glass, plants, etc. They are about 1/4 the size of a sesame seed and with a magnifying glass I can see a little white "bug" inside with a little head. It moves inside the clear shell and the shell also moves around. Any thoughts? Are they limpets? How do you eradicate them? Appreciate any help. Been raising fish for over 30 years and never seen this.