There was a bug where NPCs in normally-dark areas would not attack, even if the area was lit by a character-held light source.
Unfortunately for turquoise miners, this bug has been fixed.
Critters not attacking in dark areas, even when lit
Critters not attacking in dark areas, even when lit
[#GMCHAT] <Mirazia> I think you're enjoying this [mighty winter stuff] more than you realised
[#GMCHAT] <Rias> I AM AND IF THAT'S WRONG I DON'T WANT TO BE RIGHT
[#GMCHAT] <Rias> I AM AND IF THAT'S WRONG I DON'T WANT TO BE RIGHT