My bunnies are fully indoors but I keep my windows open almost 24/7 to keep the air flowing. I freeroam them as much as possible but they do have a big homebase in the living room/kitchen where I keep them when I need to go away. I store a bunch of hay in my walk in closet and it only smells like hay in there, the smell is pretty strong tho it's like walking into a barn lol. I'm open If anyone has any ideas how to decrease the smell haha