The Curious Life of Cows

I was over doing chores last night and noticed something that I thought was a bit odd but none the less not unusual for cows. I have a sliding door at the end of the barn that the cows have managed to knock the lower boards off of the door enough to walk through and scratch their necks on. I noticed yesterday that even though the outside of the barn is totally accessible, the cows will walk over to the end of the barn and always walk through the opening in the door and not to the outside of the building. I’m not sure quite the reasoning behind that but thought it was weird enough to mention.