Rooster Fly Pens are now available at Pasturas Los Alazanes, in Dallas, Texas. Our fly pens are imported from Mexico and come in various sizes to fit your needs. The rooster fly pen is a great way for birds to get exercise when you can’t free range. In a fly pen, the chickens will have room to fly. In a run pen, the height is just barely enough to keep them out of reach of a predator’s paw. A typical fly pen would be 8-by-10 feet and eight feet high. Stop by Pasturas Los Alazanes and shop our selection game bird pens, feeds, and supplements.