It wouldn't take THAT many... If we're talking about the queen from Aliens, I would guess around 4 or 5 experienced warriors with basic weapons could get the job done. The queen from AvP would be a much bigger problem, though. For her, I would say around 10-15 with several deaths. Predqueen from AvP Extinction wasn't that much stronger then a normal queen, just bigger and with more health. I would say around 10 Preds there.