Hickory nuts: Which rodent(s)?

As I am not able to upload more than 1 or 2 photos per post on this blog, I'm posting just a portion of the story here, and directing you to my personal blog, where I've posted the entire thing with additional photos. I would love to hear your thoughts about which animal 1. created the pile of husks, 2. left the shells that have holes on both sides, and 3. left small shell fragments. Please see entire post here:
http://ouroneacrefarm.com/hickory-nuts-rodent-sign/
...and leave your thoughts in the comment section of that post.
Thanks!
Janet