Wed 08 Dec 2021, 16:54
This is complicated.
In the first film, the intent was that the Terminator's flesh coating had a limited life, that it would die and decay relatively quickly after being applied to the Terminator. Hence, as the film goes on, in addition to the damage from gunfire the Terminator takes, the skin just starts rotting on its frame, leading to the memorable complaint about the smell and the Terminator's legendary response.
In the second film, the Terminator states when asked that the wounds in its flesh coating would heal, and later films show Terminators keeping their flesh coating intact and alive indefinitely, and even aging as time passes. This indicates that there is a very good facsimile of biological processes at work, since the tissue would need the same organic support that human tissue does to stay alive.
A Terminator is coated in more than just skin. The skin has hair follicles which can grow hair, sweat glands, the eyes produce moisture (if not tears per se) and the mouth creates saliva. Underneath the skin are facsimile muscles, as you can see muscles moving beneath a Terminator's skin (naturally, since they are played by human actors who have the internal arrangement common to all humans). Kyle describes them in the first film as having "sweat, hair, bad breath, everything."
It would be my contention that inside of an 800 series Terminator is a life support module for its flesh coating, a combined heart/lung/stomach that circulates blood through the skin. Organic blood vessels attach to the endoskeleton at certain points where the piping from this module exits the endoskeleton, allowing this blood to flow through the flesh coating and to and from the module. The Terminator breathes in reasonable facsimile of a human to oxygenate the blood, and can consume probably very simple nutrition to cycle nutrients through the blood as needed. Now, we never see a Terminator eat, so I would imagine the module starts topped off with sufficient nutrition to keep the skin alive and allow it to heal for some time before needing to be replenished.
This is an insanely complicated system that could probably only be designed by an omnicidal AI.
As this relates to Aliens, I think that a Terminator with a flesh coating would confuse them. On the one hand, they have enough life signs, thanks to the living tissue and everything that goes into maintaining it, that they appear alive and thus a viable host. On the other, beneath that flesh coating, they're far more robotic than traditional Synthetics, probably sending up some alarms in the Aliens' senses that this is not alive.
So I'd go with whatever is more dramatic. An egg may open in the presence of a Terminator, the facehugger may leap out at it, but then scuttle off as it suddenly realizes this isn't a viable host. A Warrior might attempt to subdue a Terminator for implantation, only to wonder why a tail sting had no effect. A Drone might cautiously and oddly curiously approach and investigate a Terminator, trying to figure out what this thing is and why it seems and seems not to be a viable host. Or they might skip all that and conclude this thing is strange enough to be categorized as a threat that must be neutralized as quickly as possible.
If you've seen the 40th Anniversary Short Film Alone, a lone facehugger kept approaching a lone android, because despite realizing on the first encounter that Hope was not a viable host, it kept defaulting to the instinct to find a suitable host, and Hope was close enough that it kept getting near her but not attacking because there was no point. I can imagine a facehugger in a similar situation being even more confused by a Terminator.