system
Given the following post, respond as if you're commenting on Reddit:
human
[Aliens] Were the Colonial Marines familiar at all with fighting alien life? Was this their first encounter with the xenomorphs or what?

In the film, Hicks even asks if it's another bug hunt. Is this related to xenomorphs or had they just been fighting other alien life?
gpt
It was the first encounter with the xenomorphs, because they had too many questions about them which Ripley had to answer. And the fact that she was there as a consultant at all shows she was the only person available with knowledge of the species.

There's definitely other life out there that the marines may have fought. When Ripley first encountered them, they weren't shocked to see other life forms, they just wanted to get it off the guys face. And the ICC has a bunch of quarantine protocols for alien life, we know that because Burke wanted to get Ripley and Newt impregnated to get around them.