This sparrow was picking at these seed heads for quite a long time. These plants, in both flower and seed, are attractive to various insects and birds. Sadly, it is often a fatal attraction. There have been numerous reports of birds caught by the seed heads and unable to fly away. Insects too, can become caught. I've found moths who have landed on the seed heads, unable to fly away. If they are still alive I have untangled them, a very slow chore as you can imagine, for fear of damaging the wings.