The following methods for distinguishing between venomous and non-venomous snakes are based on the experiences of many people and a compilation of features of venomous snakes. You can consider this information as a reference.
Based on Behavior When Encountering Humans
- If a snake tries to crawl away quickly upon seeing a person, it is mostly a non-venomous snake.
- If a snake coils up, flares its neck, or moves slowly, it is mostly a venomous snake.
Identifying Features of Venomous and Non-Venomous Snakes
Snake Eyes
Non-venomous snakes typically have round pupils, while venomous snakes have vertical slit pupils.
To be more precise, it is about the pupils. Non-venomous snakes generally have round pupils, whereas venomous snakes have vertical slit pupils. However, there are exceptions, such as the black mamba (Africa), cobras (Middle East, Asia, Africa), and taipans from Australia, which have round pupils.
Additionally, some non-venomous snakes can change the shape of their pupils depending on whether they feel threatened or not. Therefore, if you see a snake with round pupils, do not rush to approach it. Observe other characteristics as well.
Snake Nostrils
In venomous snakes, there is a small depression between the eyes and nostrils.
In venomous snake species, there is a small depression between their eyes and nostrils. This is a heat-sensing pit, allowing them to locate prey.
Snake Tails
The scales on the tails of venomous snakes are usually arranged in separate rows.
The scales of venomous snakes are typically arranged in separate rows, while non-venomous snakes have a pattern that divides into two interleaved columns of scales.
Snake Heads
Visually, there is not a complete difference between venomous and non-venomous snakes.
Venomous Cobra.
Typically, the heads of venomous snakes are quite large, triangular-shaped, with a small neck, and a short tail that narrows sharply from the cloaca, with clear patterns.
In contrast, non-venomous snakes have relatively small heads, oval in shape, with longer tails that taper gradually from the cloaca.
The heads of venomous snakes such as the Five-Step Snake, the Boomslang, the Malayan Krait, the Green Pit Viper, and the King Cobra are triangular-shaped, but some particularly fearsome venomous snakes, like the Krait and various sea snakes, have heads that closely resemble non-venomous snakes.
Very Venomous Krait with a Head Like a Non-Venomous Snake.
Among non-venomous snakes, there are also a few species with triangular heads, such as the triangular-headed snake, which is often mistaken for the Boomslang, leading some to call it a false Boomslang.
Color and Patterns on Snake Skin
Venomous snakes often have bright colors and may produce distinctive hissing sounds (similar to rattlesnake sounds). Of course, there are exceptions, but this is generally the case.
Additionally, if a snake’s skin has diamond-shaped patterns or features three or more colors, it is likely to be venomous.
Regarding Water Snakes
Water snakes can be either venomous or non-venomous. Venomous water snakes usually swim with their entire body floating, while non-venomous ones only float their heads, with their bodies submerged.
Based on Fangs and Bite Marks
If a snake has fangs, it is definitely a venomous snake.
There are two types of venomous fangs: first are hooked fangs, equipped with a groove for venom, some species have these fangs protruding from the upper jaw, visible when their mouths are wide open; this type of fang is called anterior fangs.
Venomous snakes with these anterior fangs often possess relatively potent venom, such as cobras, Kraits, and various sea snakes.
Some snakes have posterior fangs located at the back of the upper jaw, known as posterior grooved fangs, like mud snakes and water snakes; the venom of these snakes is weaker, so bites from them usually do not result in fatalities.
Venomous Snakes with Strong Venom from Anterior Fangs.
The second type of venomous fang is the tubular fang, consisting of a pair of long, slightly curved fangs with very small sharp tips, resembling the tip of an embroidery needle; the inside of the fang is hollow like a tube, hence the name tubular fang. The base of the tubular fang connects to the duct of the venom gland, similar to grooved fangs; when biting, the muscles around the venom gland contract, pushing the venom inside through the fang’s tube into the victim’s body, allowing the venom to spread through the bloodstream.
The tubular fangs of snakes like the Boomslang, Five-Step Snake, Green Pit Viper, and Malayan Krait are all tubular.
Therefore, when bitten by a snake, you can distinguish whether it is a venomous or non-venomous snake based on the bite marks. If it is a venomous snake, there will definitely be one or two distinct fang marks, whereas if it is a non-venomous snake, there will only be two rows of small teeth.
If it is a venomous snake, there will definitely be one or two fang marks.
What are the symptoms of a venomous snake bite?
Symptoms of a venomous snake bite include:
- Pain at the bite site.
- Swelling, redness, and bruising around the bite area.
- Nausea, followed by vomiting.
- Possible diarrhea.
- Itchy lumps on the skin (rash or hives).
- Swelling of the lips, tongue, and gums.
- Shortness of breath or wheezing, similar to asthma.
- Confusion, dizziness, or fainting.
- Irregular heartbeat.
If bitten by a cobra: Cobras, rat snakes, etc. (Colubridae family) possess neurotoxins. The bite area will be painful, and the victim will experience paralysis in the affected limb, extreme fatigue, drowsiness, fainting spells, hiccups, vomiting, and disruption of smooth muscle function…
At the bite site, there will be intense pain, visible bite marks (1 or 2), swelling around the bite, bleeding, and local necrosis. Weak pulse, low blood pressure, difficulty breathing, coma… and potentially death within 6 hours.
Symptoms of a Green Pit Viper bite: Green Pit Vipers (Vipéridae family) have hemorrhagic toxins. The entire limb bitten by the snake will experience severe pain, with red and bruised skin, and areas of hemorrhaging; the bite site will swell (and may lead to necrosis). After 30 minutes to 1 hour, the victim may vomit, have diarrhea, rapid and weak pulse, low blood pressure, and fainting…
Moreover, a Green Pit Viper bite can cause excessive bleeding, to the extent that the patient vomits blood and has blood in their stool. If correctly identified as a Green Pit Viper bite and treated with antivenom immediately upon entering the hospital, using about 10 vials of antivenom can stop the massive bleeding.
Victims of Krait bites will always feel a burning sensation in the throat, have difficulty opening their mouths, and may become unable to lift their limbs, eventually leading to limb paralysis and respiratory paralysis, causing acute respiratory failure…
If bitten by a King Cobra, the victim will experience severe pain, localized swelling at the bite site, but no necrosis will be observed; the victim typically suffers respiratory paralysis and limb paralysis.
Symptoms from Sea Snake bites resemble those from bites by cobras, Kraits, and similar snakes, resulting in muscle paralysis and hemolysis…
What to Do When Bitten by a Snake
A venomous snake bite will be very painful, and the bite site will quickly swell. You will also soon experience difficulty breathing, nausea, elevated blood pressure, muscle weakness, and fever.
When bitten by a venomous snake, the first thing you need to do is get to the nearest medical facility for antivenom (remember to bring the snake or a photo of the snake to help doctors identify it more easily). Note: Do not attempt to suck out the venom, as this may cause more damage to the surrounding tissues.
While waiting for the doctor, try to limit your movement to prevent the venom from spreading rapidly.
