Looks like a rodent dropping. Insects don't chew like this. Sometimes silverfish eat paper products in attics, but they don't fray the edges like this, and it takes them a long time. I feel confident to say a mouse, or mice, did this. Put a snap trap in the area, several would be better.
We, the family had a lot of mouse-damages including chewing several snacks and candies which the family keeping at the top of refgirator and some on counter-top/tray. We did numerous mouse traps purchased from Home Depots and Lowe's, however all of those traps didn't do any.
Afterwards, 'enough is enough,' .... we got a stray-cat roaming around on my backyard and front, that came to end several mouse-chewing and damages.
Currently, we adopted two more stray-cats, mother and her son-cat and we feed them every day whenever they came to ask us to feed them. Also, we got a very cute and nice-looking kitten born to mother-cat. All of three cats are very attached to us. Since then, we never seen any rodents/mouses anywhere in and out the house again.