Xenomorph midgame crisis

[Elimdur]

summary (details will follow later): A player empire will discover a very dangerous type of animal (either via anomaly or planet event based on pm (hostile fauna maybe)). These animals are the apex predators on their planet and it turns out they are not the product of natural evolution rather than active gene modification by an unknown empire. This presents the option to study these beasts with the intent of using them militarily (to get the xenomorph army tech you otherwise only get for genetic ascension) ... (have to check this is actually the case).
While studying them there is a chance they break out and form a hive somewhere in your colony starting periodic attacks on your colonists. The infestation may spread to other colonies (hidden in freighters and stuff). Spreading can be reduced by putting affected colonies under quarantine via planetary decision (might still spread with lower chance via smuggling ships).
Hives have to be attacked (spawning xenomorph armies and LOTS of them) in order to end the infestation.