What the heck are these? I have checked several websites and cannot seem to find a picture that matches. They cropped up about 2 weeks ago by the dozens on one corner of the tank on the glass. They just sit there and crawl up and down. They seem to be harmless to the fish. They sometimes pop them in their mouths then spit them out. Approximately 1/8 of an inch. The largest one I have seen was about 1/4 inch. The picture is an extreme close-up. Took me a while to get it focused correctly.