American Goldfinches have been dropping a LOT of sunflower seed on the ground under my feeders. While some dropped seed gets eaten, some goes to waste. And sunflower hearts turn to mush on wet ground, making them an expensive mess. As always, it helps to first watch just what is happening at your feeders and then decide what to do.
Sooner or later you will probably see a hawk at your bird feeders. When a hawk hunts at feeders, feeder birds will react. And maybe you will react too! What will birds do? What will you do?