already had chickens here?

So I am out back trying to clean the run area that is already existing on my property. It is a roughly 8x8 enclosed area with not chicken wire but something close to it as the walls. It has a door with latch and the floor appears to have some cement type base. I am not done cleaning it but it seems to have been used for some sort of animal. There is a section missing from the back that could have had a coop against it. There is no roof and it was made at the base of a large pine tree. I raked a golf ball out too.....I think it would be funny if the previous owners had kept chickens and now I am going to too!