In Aliens, the marines have fortified a position and are preparing for a last stand when the power suddenly goes out. Hudson appropriately asks, "How can they cut the power, man? They're animals!"
Later, we see that
the xenomorphs have crawled through the drop-ceiling.
Did the xenomorphs intentionally cut the power as a combat tactic, or did they
just kick something when crawling around?
Much as I hate the horrible pink slimebaby it's worth mentioning Alien:Resurrection. When the
captured xenomorphs kill one of their number in order to use its corrosive blood to escape the cell. I'd argue that this shows they are capable of advanced tactics and understand their environment and its weaknesses.
I'm willing to concede that it's no guarantee that they understand the concept of electricity... but I think we can safely say over the series that the xenomorphs are not animals as Hudson would mean it, as they possess cunning and intelligence. That they'd understand that destroying cables means the lights go out, it's not that far fetched.
Ordinary xenomorph drones are shown to have a basic understanding of cause-and-effect that allows them to learn quickly via observation, as demonstrated in Alien: Resurrection when first they turn the liquid nitrogen that's been used to control them against their captors (cause: button pushed, effect: LN2 dispensed).1
However I do not believe that understanding extends to lights and electrical wires, because the drones have not demonstrated such an understanding at any other time in the series, even at times when it would have been extremely useful/advantageous (in terms of plot) for them to have such an ability. While they can connect that pressing a switch results in a light turning on or off, they do not appear capable of conceptualising that there is some sort of connection between the two that can be interfered with.
It is true that the drones on LV-426 have, at the time of Aliens, been alive for far longer than most xenomorphs in the series, and as such they could quite conceivably have observed humans performing maintenance-related work involving wiring, thus allowing them to determine that there is a "something" between a light and a switch and that "something" is a potential point of vulnerability.
In Resurrection it is possible drones could have been exposed to an experiment that e.g. put two simple circuits next to each other, then broke the wire of one to demonstrate that the light goes out - but of course that occurs after the events of Aliens.
In my opinion, the lights going out on the Marines is due to one of two things:
The second feels like the most likely explanation, and the unofficial wiki seems to agree with this assessment.
So yes, the xenomorphs did intentionally cut the power, but it was most likely the queen and not the drones ultimately responsible for doing so.
1 The fact that the experimented-on xenomorphs in Resurrection know their blood is highly corrosive and used that fact to escape their containment, points to some sort of intrinsic (genetic?) memory inherent to the species (referred to as "hive memory" by some sources). The Ripley-clone's memories of her past, "original" self are likely due to this same ability that she was granted as an inadvertent side-effect of splicing her genes with the xenomorphs' to recreate a Queen.
In the Alien vs Predator (1999) video game, many of the Alien levels had you intentionally and methodically sabotage things to disable power or get access to targets. If that is considered canonical I would say it shows they do.
Also remember that the main reactor in the Terraforming plant was about to blow. Was this the main power for the whole planet? Unknown, but it was connected to the base for monitoring. Perhaps a huge surge from the plant caused the base breakers to blow. In the final scenes, the entire facility is throwing all sorts of electrical emissions as the reactor goes critical. That kind of activity could produce an EMP large enough to knock out a building.
No, they did not do it deliberately.
The xenomorphs do not attack for about three minutes after the power goes down, and only attack after being discovered and shot at. Any element of surprise they might have been hoping for is completely squandered by taking so long. They would have done better if the power had not been cut at all.
However, it is likely that they cut the power accidentally, rather than the power station failing, as the loss of power seems to be local. The backup lighting is red, which for some reason exists even in the air ducts(?). When Ripley & Co move on the lighting in the rest of the facility is much the same as before the power cut, with white lights everywhere. The xenomorphs were in the overhead spaces, which is a logical place to put power cables and a logical place for xenomorphs to trip over them.
This question appears to have been necro'd, so I am going to post an answer:
The "theme" of the conflict between the marines and the xenomorphs in Aliens is that the marines repeatedly overestimate themselves and underestimate the "bugs".
That is shown in the establishing scenes that introduce us to the marines - their bravado is played to the hilt, as is their disdain for "bug hunts". And they are repeatedly undone when they stroll into situations that negate their technological advantages, due to an almost absurd overconfidence.
It's in that context that we have to look at Hudson's line:
Private Hudson : What do you mean they cut the power? How could they cut the power, man? They're animals!
This scene appears to be telling us that, by our standards, they are not just animals. They have abilities we can't anticipate, and if we make our plans based on the assumption that they're just animals, we will lose. Hudson assumes that he can rely on the power, because humans are smart and xenomorphs are dumb. That assumption is proven wrong, as are all the assumptions that the marines make throughout the film.
It can have a very easy explanation that is somewhat relatable to the real world: beasts simply attack everything that vibrates or emits warmth. This behavior sometimes feels as if it is devilishly intentional, and this can be confirmed by any farmer who had to deal with mice in his shed. But it is just a coincidence: all animals seek warmth, and predator animals seek sources of sound, while our technology tends to emit most of those at its weak points.
The only intelligent thing I can remember is their tendency to hide in escape vehicles right before they launch, and not to attack crew until they land.
In the trash comedy "Tremors" this behavior is displayed in detail: monsters leave a town without communication and vehicles because they stupidly attack everything that is warm or vibrates.
I figure deliberately. If I am going to design a living weapon like the aliens, smarts would be a key ingredient. The eggs were located in a spaceship and it would be prudent to have the spawn understand the concept and running of the ship. Like the other poster said, a better example is the queen making the conscious effort to follow Ridley into space without revealing her presence in order to survive. It she was just trying to get revenge, she would have attacked the shuttle immediately. The same in Alien.
