Darklings are small, dark-skinned humanoid creatures that live in subterranean tunnels and caverns.
Darklings are always found in large groups and are aggressive, however when faced by a vastly more powerful they waste little time fleeing the scene.
Any light powered by electrical sources (grid powered, battery powered, etc.) dim and fail in a darkling's presence. The larger the number of darklings, the more pervasive and expansive the effect.
Darklings are violently allergic to all forms of light, but only natural light sources (sunlight, fire, etc.) even function in their presence. Depending on the strength of the light, darklings are burned or outright incinerated.