You could make some nets out of tulle from the fabric store. Think "bridal veil" material. The stuff is cheap, and it wouldn't be too difficult to tie it over a sunflower seed head.How do you keep other birds from stealing all the seeds before you can harvest? I tried growing some sunflowers last year, and every time I thought a flower was 'ripe' enough to pick for the chickens, the seeds were already picked out by the local wild birds! Maybe I just waited too long?