I have a freestanding wire mesh wheel for my four girls. When the wheel is up, they will fight as I don't think they have figured out yet that only one degu can run in it at a time. I'm a bit concerned as they will get smacked on the nose when the wheel is in rotation and they have had their paws and tails caught. Has anyone had any luck in preventing this from happening without removing the wheel entirely? They have had the wheel in the cage for six months and this is not new behaviour for them.