At length the photino birds appeared to come to a decision. A knot of birds, billions of them, formed around one section of the toroid — perhaps some weak point — and from all around the Ring more bird flocks flickered in short hyperdrive hops to join the growing throng. Soon only a few scouts were left near outlying parts of the Ring, and around the weak point there was a swarm of shadow birds so thick they obscured the Ring itself.
-Vacuum Diagrams, "The Baryonic Lords"