holes in garden soil

Question

What is making 3/8 inch holes in garden soil and plugging and covering them? Something is making these holes in my rototilled soil and then pulling grass and tiny sticks, etc. partially down into them so as to plug the hole. Some also have wood chips pulled over and around them, if available.

Answer 1

I suspect it was birds - either jays or crows. They are known to dig small holes to hide food (like nuts) and cover them to hide them.