Heres some food for thought. Provided by the almighty Kimarhi Ronso over on the AvP gamegossip forums.
The Alien was never meant to be just a spacebug.
Scott intentionally left that up in the air to make it scarier. As he did with the suggestion that the Alien was doing something to Lambert it wasn't supposed too. Now its easy to look at the events in Alien as either it was cleverly efficient with a much higher thinking process than people thought (consider EVERYWHERE it went and how it got everyone it did) or it was just a coincidental thing that happened randomly.
The original Alien backstory consisted of the Aliens having their own city and culture, and that they could live for hundreds of years. But their civilization destroyed by some event, the new aliens grew up ignorant of their culture and were acting on pure emotion/instinct over anything else. This is not bullshit. This is fact.
The Alien raping Lambert was implied to be a inner reflection of Kane's soul since he secretly bopped (or unsecretly bopped because sex was no big deal in the Alien timeline) her, the Alien was only acting on the desires the other man had for her. Its that kind of shit that people don't know because they use Aliens as the end all be all concerning the franchise.
But lets look further. They can still have a learning intelligence in Aliens, but they stuck with tactics that worked. The colonist had no defense against the swarming tactics, the Aliens just overran them. Lets look deeper, as soon as the marines roast the chestbursters, half the squad is killed almost instantaneously.
Before someone throws, "Da alienz were ta stupidz in the second movie," look as recently as the Iraq war to see that humans use the "swarm" tactic as well. For further proof. Try Vietnam. Or WWII. Or the Korean War. Or WWI. Where technology played a factor, but when ammo was low, it was about manpower taking a position.
There are plenty of clever things that insinuate the creatures intelligence throughout the movies. Ultimately how "open" you are to them affects how you see the creature.
Ripley's complaints about Parker and Brett fixing the lights onboard the Nostromo and then his response that they DID fix them and they couldn't understand why they were out. Coincidence or something the Alien did?
The Alien positioning itself inbetween Parker (flamethrower) and Lambert, was again somewhat clever as Parker couldn't use his weapon. Coincidence or thought out move?
How about the alien sneaking aboard the shuttle after the self destruct had been activated. Coincidence?
I find people that automatically think of the Alien as bugs never see the aforementioned scenes in that way, and in fact hardly ever notice them at all. At least in regard to the fact that the filmmakers are very subtly asking you about certain situations.
Even Cameron wanted the Aliens to cut the power. He flat out says it in the Aliens commentary on the quad dvd before the ops battle, that he thought clearly the aliens were smart and they cut the power intentionally. No accidental tripping there, an intentional sabotage of human environs, and at least a rudimentary knowledge that both A that they understand if you pull something here an area goes dark, and that b humans can't see well in the dark.
What you want the Aliens to be all depends on how you see them. Its a shame most people WANT them to be giant cockroaches. A creature you don't know much about works much better imo than one you do.
And the egging process isn't unsubstantiated bullshit either. The proof is in the film itself. Brett is for all intents and purposes an egg. The only thing that resembles a person is half his head and one hand. The rest is classic egg structure. And even with the second film in consideration, without a means to reproduce, then you wouldn't need to flame Dallas.
Also commentary, and quotes by Ridley Scott and O'bannon and Hill at what the Alien was doing to them both in the movie.
No ifs ands or buts about it, the both of them were turning into eggs.
And yes I have sources.
Don't make me bust out Alien Woman, Book of Alien, Giger's Alien, Aliens Dissected, or the novelizations of the movies. Because I am that much of an alien fanboy. *In truth nobody needs to quote the books that much, since 90% of this stuff is on the quad*