Traveller-specific . . . 

Alright.

One wonders if the Vilani had an equivalent of "God(s)-The-Literal-Father." Perhaps the Vilani credited those Ancient warbots with creating bastard children, since they were mostly active at night? The forcibly-inactive night hours were when most children would have gotten conceived (as is/was true in real world in pre-industrial societies, only more so).

Further, one wonders if - along with experiencing evolutionary selection for cautiousness - the proto-Vilani,also experienced evoluntionary selection for *quiet* orgasms or possibly even biologically-different ones? After all, someone who got too loud or whose heat signature peaked too high might attract lethal demonic attention. A reputation among "normal" human races (encountered millenia later) for staidness could easily follow from such behavioral/biological divergence.

Maybe also the occurrence of not-quite-lethal nighttime demonic encounters? The Vilani might have "Night Demon [e.g. UFO] Examination" legends and adoption of demonic surnaming practices could easily follow on from such as that.