It's about an inch or a little more across. I thought it kind of looked like one track on top of the other too, but not sure. I didn't think it was a domestic cat, but maybe? I've had cats all my life although we don't have them now our neighbors on each side both have cats. We tolerate them because they're both good mousers.
I was pretty sure it wasn't a raccoon cause I've seen their tracks before, we had them tip a can of white paint in my parents driveway and walk all over. Still have raccoon tracks on the driveway... I have no idea what the tracks look like for anything else besides that.
Thanks for helping us learn what we're looking for!
edited to add, so would a cat try to dig under a chicken run or do you think the track and the digging are unrelated?