Tell them apart
Mexican Bull Snake vs. Mexican Lancehead Rattlesnake
It matters: the Mexican Lancehead Rattlesnake is venomous, while the Mexican Bull Snake is harmless.
Mexican Bull Snake
Pituophis deppei
Harmless
- Family
- Colubridae
- Group
- Gophersnake / Bullsnake
- Size
- Large, 4–7 ft.
- Identify
- Large, blotched, with a slightly pointed snout and keeled scales — no rattle.
Mexican Lancehead Rattlesnake
Crotalus polystictus
Venomous
- Family
- Viperidae
- Group
- Rattlesnake
- Size
- Typically 2–5 ft; some species exceed 6 ft.
- Identify
- Heavy body, broad triangular head, vertical (cat-like) pupils, and a segmented keratin rattle at the tail tip.
How to tell them apart
Gophersnakes and bullsnakes mimic rattlesnakes by hissing and vibrating the tail, but they are harmless and have no rattle.
Never rely on a single feature to judge a live snake. If you cannot positively identify it, keep your distance. Informational only.