The aliens ignore you, except for the ones that are buried in the ground, when you disturb them, but running over them, they seem to get a little upset.
Much easier than having to shoot your way in. (basically, don't wear personal laser defence, that shoots automatically and fires them up!)
Oh, I forgot, I took the whimps way out and have the aliens set to not attack without provocation, however, I would have thought running them over would be considered provocation.
