Centruroides nigrescens is a medium to large bark scorpion, native to southern Mexico and parts of Central America, where it inhabits tropical forests, scrublands, and human-modified environments. It is typically dark brown to nearly black. Like other Centruroides species, it is nocturnal, commonly sheltering during the day under bark, rocks, or debris and emerging at night to actively hunt insects and other arthropods. Its venom is medically significant, capable of causing intense pain and neurotoxic symptoms in humans, though severe reactions are uncommon and the species plays an important ecological role as an effective predator controlling insect populations.