These ubiquitous round galls on the stems of goldenrods are made by the Goldenrod Gall Fly. Inside is the larva of the fly, a tempting treat for various critters. Often one can see downy woodpeckers pecking at the galls, or chickadees, sometimes red squirrels, and even mice will climb the stems and gnaw at the galls. Something has made an attempt here but abandoned it.