The worms and the oil were in the presence of humans. The worms were the fuel, but too morally ambiguous to cause problems. The humans present were the accelerant and dipshit biologist-boy who treated the snake like a pet was the match that lit the flame. If my supposition about the nature of these engineers is correct, and that they were the "Fallen Angels" and the "Destroyers" in Earth mythology, it is entirely possible that their creations lashed out at them. They probably thought that, since they were the creators of the oil, they could control their creation as well. A cardinal mistake, made many times by humans and their creations. If they are close to us genetically, it is entirely possible that they suffer from human error as well - and arrogance. Not sure about that one yet, though I have an idea - and this is all supposition on my part. There seemed to be less of the leaking canisters present in the first room with the big head and many many more in the bomber cargo hold. I would surmise that, since there were less canisters in the first room, there was less oil to distribute and contain the "bad vibes" coming off the humans. The "evil nature" being programmed into them was too much for the canisters to contain and they boiled over, whereas there were enough canisters in the cargo hold to absorb the negative energy without breaking their seals. Just a guess. Someone else on this thread coined the term "mood goo". A tongue-in-cheek description to be sure, but quite accurate nonetheless, IMO. I liken them more to a substance that absorbs and contains energy, much like battery acid (acid? hmmm...). In this case, positive and negative metaphysical energy. If a conventional battery is overcharged too much with a certain kind of battery, might it not explode? Sadly, it's not unlike the Pink Mood Slime from Ghostbusters II, methinks.