system
Given the following post, respond as if you're commenting on Reddit:
human
[Alien/Aliens/Prometheus, etc.] Is the reason life is not being found is because everything was killed by the xenomorph?
gpt
Not necessarily. Remember, space is really REALLY big so there are bound to be countless places that even an interstellar travel-capable civilization hasn't seen. 

We also know that Colonial Marines have been known to refer to certain missions as "bug hunts". While the details of their missions are all highly classified, the context it is often used in would imply that "bug hunt" refers to an actual hunt of something non-human, and because they are talking about it in reference to recently-settled locations it would stand to reason that there is life aside from our own.

What has never been found, though, is INTELLIGENT life. It sounds like any life that has been discovered is a nuisance at best. The discovery of the Xenomorphs, and later the Engineers, was our first confirmation that intelligent life exists outside of Humanity.