Where do pigs sleep?

Mostly in the summer they turn over up some fresh dirt and plop down either in the sun or shade, but when they want some shelter  they head for these little gizmos called Port-a-Huts. Toss some straw in , and the pigs love them. Shannon moves them about using the bucket on our tractor. You can put on doors that cover 1/2 the front, but as you can see our hogs tend to blow them right off. One down....three to go .