The problem with this comparison is the ultimate goal. Predators are not invaders in the martial sense. They come down to Earth to hunt. They pick off a few humans that can defend themselves, collect their spines as trophies and go home. They don't go after humans that can't offer a decent fight. The one that spared Maria Conchita didn't necessarily care about the baby. He probably just thought a woman who was pregnant would be less physically capable of defending herself than one who isn't. Again, this is not evidence of any ethical sense on the part of the aliens. The Battleship aliens are invaders in the martial sense. They sent troops and ships and immediately set about trying to achieve strategic goals. They closed off the area around the Hawaiian Islands to almost all ship and air traffic, then used the ships they brought to deal with the ships they missed and used the troops to take and hold the NASA station to use as a comms station. Yes, they let one ship go when it backed down, but then they had to deal with that same ship over the next several hours, and after it finally decided to sink the thing, it let the crew get to another ship to finish the fight and destroy their comms station, which got compromised because they let some NASA geek and a physical therapist with nice tits do whatever they pleased without incident. On the face of it this looks chivalrous, like with the Predators, but it's just as likely that the aliens were suffering from mind-blowing stupidity. This is a problem in a literary sense, because chivalrous/stupid aliens that will let you screw them as long as you're not acting aggressive are not scary, and alien invaders that don't frighten anybody make for horrendous alien invasion movies. The aliens in Battle:LA were frightening on some level. So were the aliens in Independence Day. The aliens in this movie were a joke. Which brings me back to my original comment, which had nothing to do with any code of honor on the Hirogen's part. The Hirogen were non-scary aliens the typically clueless writers of Voyager tried to pass off as Predators, while the Battleship aliens are non-scary aliens that the writers of this movie tried to pass off as War Of The Worlds Martians, and the one thing the Hirogen have over the Battleship aliens is that the Hirogen at least talked once in a while. This is why I said don't think too hard about this. We're talking about stupid aliens in a stupid alien invasion movie. No that was the Under Siege moment. Literally stolen from a Steven Seagall movie... The Hornets came off the carrier once the barrier was down. In Independence Day several pilots were on leave, leaving several planes available after the aliens' initial attack. And yet, Armageddon was still a better movie.