[Combat tests reveal that ~(30/30) times, Xom bites things' heads off. I pretty much just copied the Giant Cave Spider raws, made everything gabbro, and upsized him quite a bit, but yeah. I haven't seen him do a single non-head non-bite attack.]
You take a mental step back for a bit. Now, these creatures are odd, as you've never seen anything with such a shell, or such supple beards (once you saw a troglodyte with a sad little lip-warmer, but that was long ago). But they have the secret of the purple liquid, the ability to craft things out of metals, and they can break free of the caverns! What lies above? Why are they not accustomed to the darkness like you are, instead lighting their path through artificial means? These mysteries must be solved! And while webbing these three chumps may give you some time to pore over their works in other chambers attached to the stairwell, these troglodytes will certainly raise the alarm if they storm the building, and you're sure there are more than three in these chambers. The best solution is to try to work something out with the beards.
You can either kill the trigger-happy trogs, or try to disarm the bearded men, but they may flee, and you don't really do non-lethal combat. You leap on the troglodytes and rip off their heads, and blood sprays everywhere, coating your gabbro face (which probably won't help you when it comes to not scaring the beards). Before the beards have time to run away, you tap a still-remaining spill of the purple liquid and look expectant.
They are stunned, and run away as fast as they possibly can, babbling among themselves once more. You turn around and are just about to amble back into the cavern to wait when a troglodyte jumps up from nowhere and looks very angry. You web him and another troglodyte suddenly emerges from behind a mushroom, only to run away at maximum troglodyte speed. The beards' voices are still far away, but it sounds like more are beginning to speak up as well. Now what?