Iseijin,
Yautja,
12 years ago
That's what's fun about xenomorphs. They are a malleable enigma. We barely know anything about them, but it's as though almost anything is plausible.
They don't need to eat, but they have stomachs and intestines.
They don't need to breathe, but their chests heave with breaths.
They do not need shelter, yet still build intricate hives.
We don't know how they think. Yes, they are connected to the Queen's hive mind, but when there's only an individual around they've proven to be smart enough to be classified with a sort of self-awareness conscience. It's all so baffling and contradicting, but it works. They are adapted for all sorts of environments - even lack of it altogether (space)! - that these internal systems must serve a function when they need it; and if they don't need to then they don't use it. Simple as that. Maybe they don't NEED to eat, but do to absorb nutrients and help their metabolism. Maybe they don't NEED to breathe, but do because the environment supports an atmosphere that can transmit scents and pheromones. Maybe they don't NEED shelter, but build hives to keep the drones together.
It's all speculation. Go nuts.