The large, mushroom-shaped structure on the Swarm Hosts back is a breeding ground that weaponizes the millions of diminute larvae inhabiting the creatures bloodstream. Through a simple system of membranes for matter exchange, glands that pump the offspring full of hormones to hyperaccelerate growth, and ducts for efficient transportation to the bubbling pockets on the surface of the Incubator, the Swarm Host births deadly, short-lived Locusts to destroy threats to the Swarm.