Reptiles
Black-necked Spitting Cobra
Naja nigricollis · also called black-necked spitting cobra, spitting cobra
The black-necked spitting cobra has a ranged weapon. Cornered, it rears up and fires two fine jets of venom straight at the face of whatever is threatening it, aiming for the eyes, from up to three metres away. On the skin the venom does nothing; in the eyes it causes agony and, untreated, can blind.
Overview
Black-necked spitting cobras live across sub-Saharan Africa, in savanna, grassland, dry forest, and farmland, and they adapt readily to villages and buildings, which they enter hunting rats — bringing them into frequent contact with people. They are active hunters, mostly nocturnal, eating rodents, other snakes, amphibians, and birds. Colour varies enormously across the range, from all black to grey, olive, red, and banded.
Spitting
The snake’s fangs have forward-facing openings near the tip. Threatened at close range, it spreads its hood and squeezes its venom glands, ejecting venom as two fast, fine jets. It aims at the face and tracks movement, hitting the eyes accurately from 2–3 metres, and it can spit repeatedly — and bite in the same encounter.
- On intact skin: harmless
- In the eyes: immediate severe pain, swelling, and — without prompt flushing — corneal damage and possible blindness. First aid is to irrigate the eye for 15–20 minutes with any bland liquid, then seek care. Antivenom is not used for eye exposure.
The bite
A bite injects a strongly cytotoxic venom that causes major local tissue destruction — pain, swelling, blistering, and dying skin and muscle — often needing grafts or amputation. Whole-body effects are usually milder than a non-spitting cobra’s, but a bite is still an emergency needing antivenom.
Why spitting evolved
Spitting is purely defensive and has evolved independently at least three times in cobras. A 2021 study linked the timing of these origins to the rise of upright, tool-using early humans — a ranged deterrent against a threat that can see the snake and kill it from a distance.
Status
The black-necked spitting cobra is Least Concern, common and widespread, and thrives around farms and settlements.
Black-necked Spitting Cobra: common questions
How does a spitting cobra spit venom, and how far?
The fangs of a spitting cobra have their venom-delivery opening rotated to face forward, near the tip, rather than pointing down as in a biting snake. When the snake feels threatened at close range, it rears up, spreads its hood, and sharply squeezes the muscles around its venom glands, forcing venom out of those forward-facing holes as two fine, fast jets. The black-necked spitting cobra can direct these accurately at a target's face from about 2 to 3 metres, and it aims at the eyes — it tracks the face and reacts to movement, so a person who ducks or turns is still likely to be hit. A single "spit" can be repeated many times, and the snake can spit and bite in the same encounter.
What happens if the venom gets in your eyes?
It is intensely painful almost immediately — a burning, stinging sensation — followed by profuse tearing, swelling of the eyelids, redness, and blurred vision, because the venom's enzymes attack the surface of the eye. If it is washed out quickly and thoroughly, most people recover fully within a day or two. If it is not irrigated promptly, the venom can cause ulceration and scarring of the cornea and, in serious cases, permanent partial or total blindness in the affected eye. The first aid is to flush the eye continuously with large amounts of any bland liquid — water, saline, milk — for at least 15 to 20 minutes and then get medical care. Antivenom is not used for eye exposure; irrigation is the treatment.
Is a spitting cobra bite worse than a normal cobra bite?
Different, and in some ways worse locally. The black-necked spitting cobra's venom is strongly cytotoxic — it destroys tissue at the bite site, causing severe pain, swelling, blistering, and death of skin and muscle over the following days, which frequently leads to lasting disfigurement, skin grafts, or amputation of a digit or limb. The whole-body effects — on breathing and the nervous system — tend to be less severe and less rapidly life-threatening than those of the neurotoxic Asian cobras or the mambas, but the bite is still a genuine emergency requiring antivenom, and untreated bites can kill, especially in children.
Why did spitting evolve in cobras?
Spitting is a purely defensive adaptation — it is not used to catch prey, which cobras still subdue by biting. It has evolved independently at least three times in the cobra group, and a 2021 study found that the timing of these independent origins in Africa and Asia broadly coincides with the emergence and spread of bipedal hominins. The proposed explanation is that a ranged deterrent — one that can hit the eyes of a large, upright, close-range threat before it strikes the snake — became valuable specifically because of the pressure from early humans, who could see the snake, approach on two legs, and kill it with tools or thrown objects. It remains a hypothesis, but a well-supported one.