The Coal Skink (Plestiodon anthracinus) is a small, secretive lizard native to North America, typically found near moist, wooded areas. Due to its quick movements and dark coloring, people often wonder about its potential threat level. This species is harmless and poses no danger to humans or household pets.
The Definitive Answer: Toxicity Status
The lizard is neither venomous nor poisonous. It cannot inject toxins via a bite or sting, nor does it contain toxins harmful if ingested. The Coal Skink lacks venom glands, fangs, or toxic skin secretions that could cause injury. The misconception that skinks are harmful may stem from regional folklore, where young skinks are sometimes mistakenly called “scorpions” and thought to have a venomous sting. This is entirely false, and no lizards in the southeastern United States are considered dangerous to people. The Coal Skink is purely a predator of small invertebrates and lacks chemical defenses. While an adult skink might deliver a firm nip if handled, the bite is non-toxic and generally not painful.
Identifying the Coal Skink
Adult Coal Skinks are slender lizards reaching 5 to 7 inches (12.7 to 17.9 cm) in total length. Their smooth, overlapping scales give the animal a distinct glossy appearance. The body color ranges from olive-gray to dark brown, highlighted by four thin, light-colored stripes running from the head onto the tail. A broad, dark stripe on each side, from which the common name is derived, spans the length of the body. During the spring breeding season, adult males may display reddish or orange coloring along the sides of their heads. Juveniles are much darker, often appearing black, but are easily identified by their strikingly blue or reddish tail.
Understanding Skink Defense Mechanisms
Since the Coal Skink cannot rely on toxins, its survival depends on non-chemical, behavioral defenses. The most recognized of these is caudal autotomy, the ability to voluntarily detach its tail when grasped by a predator. This is made possible by pre-formed fracture planes within the tail vertebrae, allowing for a clean separation. The detached tail continues to writhe and twitch vigorously, creating a powerful distraction that diverts the predator’s attention away from the fleeing lizard. The brightly colored blue tail of a juvenile is especially effective, acting as a visually appealing target. When pursued near water, the lizard may also quickly dive in to hide beneath rocks or debris to escape capture.