Thought I would make a few additional comments about these large round bales while I think about it.
They are not always bound with hay in them. Many farmers bale the stalks from corn and soybeans after combining for bedding. These are bales of corn stalks.

Once any form of these bales are stacked in rows on the edge of a field they serve as automatic corridors for animal traffic as in this example:

To the immediate right of the base of the hay bales on the far left there is a dark green patch of grass. If you look closely, there is a linear animal trail next to it. After closer examination, I could tell that it was being used by fox, coyotes and raccoons. Those bales are about 50 yards west of a rundown abandoned barn for reference.
Jonathan