Could it have no "sense of self?" Could it be more like a swarm with implausibly uncanny optimization capabilities than a Mind from one of the Culture novels? Perhaps it would be like a "hegemonic swarm" from one of those books.

Is human civilization as a whole such an entity? I can look at humanity as a whole with a mindset, such that all of human civilization and culture can look like a "soulless, monstrous, hegemonic swarm."

What would entities that do have a sense of self, but no compatible concept of sex and mammalian politics seem like?

I read in The Selfish Gene that spiders are wired with the evolutionary stable strategy of always buckling when confronted by an invader in a territorial dispute. This works because all spiders are so wired, so overly rigorous territory battles are avoided. It's evolutionarily stable because a contrarian spider born in such a population would get the tar beat out of it. It seems that human beings tend to defend their territory. Perhaps there's a race of aliens who are great explorers because members of their species are wired like spiders and so are always being pushed outwards. If they encounter us, they might expect us to vacate our planet. This thought makes "invasion" stories a smidgen more likely, though it's just a smidgen in comparison to all the other implausibility in such stories.