This structure appears to be the source of all Alien eggs. Few Aliens enter the building but many are seen to leave. Our Scientists fear the existence of a frightful Alien Queen. Exercise extreme caution if you encounter such an Alien.
The Spawning Chamber appears to be a very special structure. Very few Aliens enter this structure although vast numbers of Aliens regularly leave the building. Our research indicates that this building is the lair for some kind of Alien queen. We believe this Alien to be the sole producer of Alien Eggs from which all Aliens hatch. Whilst the primary objective is the destruction of the Queen and all Alien Eggs, the live capture of the Alien Queen would be a vicious insult to the Aliens.
Most of the mission area is taken up with a large central structure containing the Queen and four reinforcement pads. There are a few extra reinforcement pads scattered around the map. The queen is immobile and isn't going anywhere, so clear out the rest of the map, kill the aliens in front of the Queen from outside her vision range and dart in and vortex mine the reinforcement pads. Then it's just you and then Queen and you can take your time stunning and capturing her.