This is just under the upper rim on the outside of my upper biofilter tank for the outside aquarium. Anyone have an idea what buggy thing this is? Click the image and enlarge.
I know it’s buggy, just not what flavor of bug. Whatever was inside the mud or exudate shell is no longer there. The outside is covered with round . . . they can’t be seeds. They might be eggs but they aren’t like any egg I’ve ever seen. They’re round with a tiny dimple in the face.