Northern water snake The belly also varies in color. It can be white, yellow, or gray. Usually it also has reddish or black crescents. The northern water snake is nonvenomous and harmless to humans, but superficially resembles the venomous cottonmouth and is often killed unnecessarily as a result of this mistaken identity. The two can be easily distinguished by morphological traits: the water snake has a longer, more slender body and a flattened head the same width as the neck, round pupils, and no heat-sensing pits. The cottonmouth has a fatter body, a wedge-shaped head with prominent venom glands that are wider than
Venomous snake to subcutis (SC), vein (IV), muscle (IM or IC), and peritoneum (IP). The former (SC) is most applicable to actual bites as only vipers with large fangs, such as large "Bitis", "Bothrops", "Crotalus", or "Daboia" specimens, would be able to deliver a bite that is truly intramuscular, and snakebites rarely cause IV envenomation. Testing using dry venom mixed with 0.1% bovine serum albumin in saline, gives more consistent results than just saline alone. Belcher's sea snake ("Hydrophis belcheri" ), which many times is mistakenly called the hook-nosed sea snake ("Enhydrina schistosa"), has been erroneously popularized as the most venomous snake