How to Tell Venomous vs. Non-Venomous Snakes Apart Venomous Snakes: What to Look For Triangular Shaped Head Elliptical cat-like Pupils Visible Nostrils Heat-Seeking Pit Organs 醴 Large Hollow Fangs Body Narrower than the Head Tail Clues: Scales on the underside of tail: Single row Rattlesnake tail: made of loosely linked buttons Anal plate: divided Non-Venomous & Coral Snake Round Shaped Head Round Pupils 醴 Small Teeth 領 Fixed Jaw Body width blends with the head Tail Clues: Scales on the underside of tail: Double row Note on Coral Snake: Although it has round pupils, the coral snake is venomous! It has hooked teeth instead of fangs.