#worm adjacent

for an actual answer, real life flechette darts are mostly fictional, except for their use in the raytheon knife missile or being dropped out of planes in world war 1. But darts are real things! they're pretty rare, at least at the size you'd call it a dart. Usually, when people say "a thrown dart" they're basically referring to a spear or javelin. Teeechnically it's an "atlatl dart" but like it's extremely similar to a throwing spear. and. look if any weapon is phallic then its definitely a throwing spear.

But a smaller dart, similar to a throwing dart? those weren't really used in war (technically the romans used a very similar concept, but in any case it was pretty short-lived), and lily's use of them in worm is more-or-less invented by wildbow, since by the time Flechette Darts were invented, humans had invented better (and less hot) ways to propel them than throwing, and the people in charge of wars are sexless jackanapes.

There are throwing-dart style weapons that do exist, you can find youtube videos about them, but they aren't commonly used and are more of a tool to show off than a legitimate weapon. So anyone using one is probably very skilled!