Board Thread:Warhammer 40k General Discussion/@comment-24059665-20131122182800/@comment-7671639-20131204151848

Also remember, unlike the orks, the Tyranids evolve at an astonishing rate. The nids are getting bigger and their bodies are changing to better kill ork. The only reason in Octavious that they haven't completely pole drived through the Orks is that every ork in 10 lightyears is coming on that one planet to fight them. But they are slowly winning, for every Tyranid and Ork that dies it adds more biomass to the swarm. (According to the recent Tyranid Codex).