Thanks Husky Mom for the reply! Oh, and of course I would never house them in the same cage lol! The rats have a nice and big cage on one side of the room and I would place the budgie cage on the other side, but I'm still worried because I think birds can get mycoplasma but I don't know if it's the same strain rats get. Also, the budgie cage I'm getting is 30 inches long and 18 inches wide and 18 inches tall, so the bird will definately have adequate space!