4th faction revealed at last?

We haven't been fighting Terminids this entire time. We've only been fighting their reanimated corpses. According to official lore, Terminids used to be a sentient, peaceful species until...something happened. I believe E-710 isn't only created by the decomposition of Terminids. It's created by the [redacted] fungus, Terminids and human bodies combined. That's why you'll stumble upon graves with Terminid larvae consuming human corpses. All this to say: our starships are not only powered by Terminids, they are powered by....us.