The term “black snake” applies to several distinct species across North America that share a dark dorsal coloration. For accurate identification, examining the ventral side—the belly—provides reliable characteristics, as the color and pattern of the scales vary significantly between species. While some black snakes are uniformly dark, others feature bellies that are white, cream, or a mottled mix of light and dark scales. Understanding these differences helps distinguish between the two most commonly encountered black-bodied, non-venomous snakes: the Black Racer and the Eastern Rat Snake.
Which Black Snakes Have Light Bellies
The two most common species with predominantly black backs and light-colored bellies are the Eastern Rat Snake (Pantherophis alleghaniensis) and the Black Racer (Coluber constrictor). The Black Racer is solid black along its back, featuring a uniform white, cream, or pale yellow color extending from the chin down the length of its underbelly. This ventral coloration is clean and unpatterned, making it a key distinction for this slender species.
The Eastern Rat Snake also has a light-colored belly, but its pattern is distinctly different from the Racer’s. The Rat Snake’s belly scales are typically white, gray, or yellowish, marked with a prominent checkered pattern of black or dark brown spots. This pattern is a remnant of the blotched coloration seen in their juvenile stage and is especially noticeable toward the tail. Both species tend to have a bright white or cream-colored chin and throat, which is visible when the snake is at rest.
Differentiating Features Beyond Color
While belly color provides a strong clue, other physical and behavioral traits are necessary to distinguish between these species. The clearest structural difference lies in the texture of the scales on the back. The Eastern Rat Snake possesses keeled scales, meaning each scale has a raised ridge running down its center, which gives the snake a duller, rougher appearance.
The Black Racer is covered in smooth scales, which contributes to its glossy, polished look. Beyond scale texture, their body shapes are distinct; the Rat Snake is robust, heavy-bodied, and appears somewhat loaf-shaped in cross-section with a flattened belly. The Racer is much more slender, whip-like, and cylindrical in cross-section, reflecting its reputation for speed and agility.
Behaviorally, the Rat Snake is an accomplished climber that utilizes its flattened belly and strong musculature to ascend trees, walls, and rafters in search of prey. When threatened, a Rat Snake may freeze in a kinked, defensive posture. The Racer is more often observed on the ground and relies on its speed to evade threats, pinning down its prey rather than using constriction.
Geographic Range and Habitat
The geographical location where a snake is encountered can serve as a final piece of evidence for confirmation. The Eastern Rat Snake is widely distributed across the eastern half of the United States, stretching from New England south to the Carolinas and west into the Great Plains. This species is adaptable and thrives in varied environments, including dense forests, rocky hillsides, farmlands, and suburban areas.
The Black Racer shares a broad range across the eastern US, but favors more open and sun-exposed habitats. Racers are frequently found in meadows, brushy fields, forest edges, and along fence rows where they can bask and actively hunt. Their preference for open areas reflects their active, visual hunting style, which is optimized in environments with less obstruction.