The Helmacron shouted a command in shockingly loud thought-speak. <Male! Male, here!> A hatch in the floor opened. And up through the floor poked a trembling head. It was like the other Helmacrons, but smaller. The flat head had a forward slant. The mouthparts were less horrifying. Still insect-looking, but smaller, gentler. The entire bearing of this creature was humbler. <Male, take these aliens. Instruct them in the ways of obedience!> The Helmacron shoved us toward the hatch. "Male?" Marco wondered. "Did he . . . I mean, was that . . . is this . . . " "I think so," I said. "The loud, hyper ones are females. This is a male." "Oh, man. Now I'm really scared. It's an entire species of Rachels." p. 81-82
Marco, you better mean that in the sense of women that are willing to fight. Because beyond that, there isn't much that is similar between Rachel and the Helmacrons.
And yeah, it makes sense that at least one alien species that we run into is going to be a matriarchy. There is no reason for all of them to be patriarchies. Just looking around at the species on Earth and we know that some are lead by the female members of the species.












