No More Hosts, What Next?

Gavin
MemberTrilobiteMay 01, 20122619 Views23 RepliesA theoretical question for you all, here's the scenario...
A planet, somewhere out there, full of life. Not intelligent life like us (an exaggeration I know), but wildlife, much like Earth was during the Cretaceous period (last era of the Dinosaurs). There is only one continent on this planet.
Down through the clouds a Derelict/Juggernaut descends, and hovering silently above the ground it deploys its cargo of Xenomorph/Alien eggs before ascending back above the clouds and leaving the system.
The contents of the eggs do their thing... Facehugger - Chestburster - Alien and Queens - Hive - Eggs. The cycle continues, on and on, hive after hive is established and the number of indigenous lifeforms from this planet that are suitable as hosts for the Xenomorph/Alien grow smaller and smaller in number.
My question is, what happens when all suitable hosts are used up? What are your theories as to what happens next...