system
Given the following post, respond as if you're commenting on Reddit:
human
[Warhammer 40k] Won't the Tyranids eventually win?
gpt
They Tyranids can only win if their battles are more energy efficient for them than they are for the enemy. If they are unable to reclaim the biomass after victory, then they suffer a net loss and cannot continue to propagate. If you view the tendrils of the hive fleet invasions, you can visibly see the worlds they strictly avoid are Necron Tombworlds, since they are never able to acquire biomass from battles with the necrons due to their 'phase out'.