The Hut

Abandoned, rusty, broken and useless, this little hut sits in a field near us. Year after year, it stands there in the sun, window missing, serving no purpose. Nothing is stored in it, nothing lives in it (apart from a few spiders, perhaps).
Was it ever used as a shepherd's hut? as a hay store? Why did they put in a window?
These unimportant questions come into my mind sometimes as I walk past - but mostly, I hardly notice it. When the sheep are in the field, they sniff around it, but they're not really interested. They'd rather shelter by the hedges.
My dog, normally curious, has never been inside it.
Why?