i have wondered for a long time whether aliens were male or female.
i heard one story that said:
drones, warriors and preatorians were male and queens were female.
another that says:
they are all neither male nor female but something inbetween.
that all the aliens are female becuase they can all turn from warrior to queen.
personally i feel that they are both sort of due to the fact the are all capable of becoming queens. and also becuase they probably did not follow the same evolutionary path as life on this planet, so they are infact asexual. becuase if they were all female then the species would die out. there would be have to be at least one male to breed with the queen wouldnt there? in which case a male alien probably a "king" would have appeared in the alien saga thus far.
although it could be debatable throughout most of the series whether there was a king and we just did not see it, the films alien resurection and avp requim proove that there is no male alien to breed with the queen.
prehaps they have evolved above the need for the species to be divided into sexual groups, to have natrul uniformity.