I would think it would be a waste of energy and would just create a white blob waving around in the tree to attract attention. Styrofom probably absorbs as much sound as it would hope to direct outwardly. Usually you don't want to create a BIG noise.... just enough for them to hear and get curious about. I'd say bull hockey... not worth the effort.Besides that, we don't need all those lost styrofom cups polluting the woods. Keep them at home.