The seed thief

When we moved in here and I started rearranging the backyard there was a volunteer sunflower (well, a lot of volunteer sunflowers) that came up. I let one grow and grow and grow until it had a gigantic head on it. I figured it'd feed the birds come fall or winter. As soon as the seeds ripened they seemed to be going pretty fast, and in rows from the top like a person would eat corn on the cob. I never saw a single bird eating them though. Then, one day I look out the kitchen window and see this....
He (or she) ate every seed on there within a week.