Which features identify poisonous snakes in Tennessee?

• A. Elliptical pupil, a pit between the nostril and eye, and undivided tail scales
• B. Round pupil, no pit, and divided tail scales
• C. Triangular head with stripes on the body
• D. Slender body and smooth scales

Answer: (A)

In Tennessee, the most reliable way to spot venomous snakes is by recognizing pit vipers, which carry a combination of features that set them apart. The key cue is a pupil that is elliptical or slit-like, not round. Along with that, pit vipers have a heat-sensing pit between the nostril and the eye, a distinctive groove-like organ they use to detect warm-blooded prey. They also have undivided tail scales, meaning the scales on the underside of the tail form a single row rather than being divided into paired scales. Seeing all three features together strongly indicates a venomous snake in this region.

If any of these cues are missing, the snake is much more likely to be nonvenomous. A round pupil, no pit, or divided tail scales point away from pit vipers. Likewise, a triangular head or stripes alone aren’t definitive, since many nonvenomous snakes can mimic that look. Slender body and smooth scales aren’t reliable indicators by themselves either.