This reminded me of another story that I vaguely remember (it's partly why I had
to listen to this in the first place), but I just can't recall the details. There were small assassins with similar weapons, possibly flying on dragonflies or small birds. Does anyone know which story that could be? I'd love to know
Perhaps you are thinking about the Gallivespian race in Phillip Pullman's His Dark Materials trilogy (the first of which was adapted into the movie The Golden Compass). They were little people who rode on dragonflies, had poisonous spurs on the backs of their heels. Because they were small and hard to detect and had inborn weapons, they make good assassins.
(I am not a fan of the trilogy in general, and could rant for a long long time about it)