system
Given the following post, respond as if you're commenting on Reddit:
human
[Warhammer 40K] I find myself stranded on a planet about to be besieged by a Tyranid Hive fleet. How likely am i to survive if i somehow hide inside, for instance, a very well hidden, deep underground bunker ? What if i am a Blank individual ?

Let's say i got words that a Hive fleet of Tyranids is attacking the other side of my planet, a simple planet with a few garrisons. I happen to have a deep underground bunker with nobody inside and a relatively hidden door. Can i lock myself up inside and hide until the Tyranid hive fleet has devoured the planet entirely and leaves ?

What if the bunker is independant in terms of air production and food / water supplies ? What if i decided to bring my friend who is a Blank individual ?
gpt
You could possibly survive the initial attack, yes. They don't physically destroy the planet. They do mine into the ground but if you're lucky they'll miss you. They don't go everywhere, and if you're away from underground life or mineral deposits, you might well make it.

You would then be trapped on a completely barren planet stripped of all biomatter and resources including water, with all infrastructure utterly destroyed, that everyone else in the galaxy assumes is completely lifeless, in a small bunker with a person who's supernaturally unpleasant to be around, under a culture with decent odds of considering you a traitor for hiding rather fighting the Xeno threat.

You might survive the initial invasion, but not long after. Honestly, it'd probably be quicker and kinder just to walk into the swarm.