I've changed nothing in the past few weeks =(
These are most definitely not snails. They move far too fast, and free swim as well as sit on the glass.
There are some that are bigger and some that almost look like teeny tiny tadpoles. In shape, I mean.
I'm honestly not sure if they have BEEN there longer, and I'm only now noticing them
(I only noticed on random chance, lecustic was being adorable and putting her feet in the glass and I went to get a picture, and saw something moving) or if they've only just popped up.
My grandfather put a new pellet type into the automatic feeder a few days ago, actually. These little green sinking pellets for amphibians and tadpoles, or so he says. When I noticed I took them all out (the axies where completely uninterested anyway) but...could those be the source?