I recently added several guppies, two otocinclus, and two plants to my tank. One night, after I had those for a while, I was staring at my tank when I noticed some spots on the side of the glass. When I took a closer look I noticed they moved. Then I watched longer and saw some of them swimming around. I've been doing a lot of searching on the net and I'm not sure I'm satisfied with the info I've found. They are just little specs about the size of a period (.) or so. They spend a lot of time on the glass or on my plants. When I have described them to a few people they suggested they might be fish lice so I looked that sort of thing up. I've been looking stuff up and watching my tank for at least a week now and what I have noticed is that I never see these things on my fish. I look real long and hard and I only see them on the glass or on my plants,especially decaying leaves, and swimming around. Does anyone have any idea what I'm dealing with. I'm not as worried as I was because like I said they don't seem to bother my fish.......