Identifying whether a snake is venomous or non-venomous can be crucial for safety, especially in regions where snake encounters are common. While physical characteristics like colour and head shape provide some clues, understanding a snake’s behaviour can offer deeper insights.
Venomous snakes often exhibit distinct defensive behaviours, feeding patterns, and movement styles that set them apart from their harmless counterparts.For example, venomous species may display warning signs such as rattling their tails or adopting aggressive postures when threatened.
In contrast, non-venomous snakes typically exhibit more non-confrontational behaviours, preferring to escape rather than engage. Explores the key behavioural traits of snakes, helping you differentiate between venomous and non-venomous species, thereby enhancing your awareness and safety when encountering these fascinating reptiles.
Key characteristics of venomous vs non-venomous snakes
| Characteristic |
Venomous snakes |
Non-venomous snakes |
| Head Shape | Triangular or wedge-shaped, wider at the back | Round or oval-shaped |
| Pupil Shape | Slit-like, elliptical pupils | Round pupils |
| Colouration and Patterns | Often brightly coloured with distinct patterns (e.g., red, yellow, black) | More muted colours or solid shades |
| Tail Characteristics | Rattles (e.g., rattlesnakes), bright colouration in young (e.g., cottonmouths) | No rattles, often uniform in appearance |
| Body Size and Shape | Typically stockier and more robust | Can vary; some large non-venomous snakes resemble venomous species |
| Defensive Behaviour | Rattling, hooding, aggressive postures | Flattening, non-confrontational behaviour |
| Feeding Behaviour | Ambush predators, staying still and camouflaged | Active foragers, moving to locate prey |
Difference between venomous and non-venomous snakes
Head shape
One of the most noticeable differences between venomous and non-venomous snakes is their head shape. Venomous snakes typically have a triangular or wedge-shaped head that is wider at the back and narrower at the neck.
This shape is particularly prominent in pit vipers, such as rattlesnakes and copperheads. However, it’s important to note that some non-venomous snakes can flatten their heads to appear more triangular, which may lead to misidentification.
Pupil shape
Another distinguishing feature is the shape of the pupils. Venomous snakes usually have slit-like, elliptical pupils, similar to a cat’s eye. In contrast, non-venomous snakes tend to have round pupils. Observing the pupil shape can help, but be cautious; it’s best to maintain a safe distance when trying to determine this feature.
Colouration and patterns
Colour can also provide clues about a snake’s venomous status, although it’s not always a reliable indicator. In the United States, many venomous snakes exhibit vibrant colours or patterns, which may serve as a warning to potential predators. For instance, coral snakes have distinct red, yellow, and black banding.
Conversely, many harmless snakes feature more muted colours or solid shades. A common rule of thumb is that brightly coloured snakes are often venomous, but exceptions do exist, so caution is advised.
Tail characteristics
The tail can be a significant indicator of a snake’s type. For example, rattlesnakes possess a rattle at the end of their tails, which they use as a warning signal. Young cottonmouths and copperheads also have bright yellow or greenish-yellow tails. While some non-venomous snakes can mimic rattling sounds, it’s better to be on the side of caution if you hear any rattling.
Body size and shape
Many venomous snakes tend to be stockier and have a more robust body compared to non-venomous species. However, this can vary significantly between different species. For instance, a large non-venomous snake like a boa constrictor may easily be confused with a smaller venomous snake.
Defensive behaviour
Snakes, especially venomous species, often exhibit distinct defensive behaviours when threatened. Here are a few notable examples:
Hooding: Cobras and some other venomous snakes expand the skin around their necks to create a hood. This behaviour makes them appear larger and more intimidating to predators. It’s a warning sign to stay away, as they are equipped to defend themselves if approached.
Flattening: Non-venomous snakes, such as rat snakes or garter snakes, may flatten their bodies and attempt to appear larger when threatened. This behaviour can mimic the defensive postures of venomous snakes, making it harder for predators to identify them accurately.
Feeding behaviour
Many venomous snakes, such as vipers and pit vipers, rely on ambush tactics. They remain still, camouflaged in their environment, waiting for unsuspecting prey to come within striking distance.
Non-venomous snakes like rat snakes actively seek out their prey. They will move through their environment, using their keen sense of smell (via their forked tongues) to locate food. This behaviour differs from the ambush style of many venomous species.
Practical tips for safety
When encountering a snake, safety should always be your top priority. Here are some guidelines to follow:
- Stay calm: If you see a snake, remain calm and avoid sudden movements. Snakes are generally not aggressive and will often retreat if given space.
- Observe from a distance: If you can safely distance yourself, take note of the snake’s features without getting too close.
- Identify before approaching: If you must approach the snake for identification, do so with extreme caution.
- Know local species: Familiarise yourself with the types of snakes in your area, focusing on the venomous varieties.
- Leave the snake alone: If the snake is non-threatening, it’s best to let it be and allow it to move on its own.
What to do if bitten?
If you are bitten by a snake, treat it as a medical emergency, regardless of whether you think it’s venomous or not. Here are the steps to take:
- Stay calm: Panic can increase heart rate, spreading venom more quickly.
- Keep the affected limb still: immobilise the bitten area and keep it below heart level.
- Seek medical help: Get to the nearest hospital or call for emergency assistance.
- Do not: attempt to suck out the venom, apply ice, or use a tourniquet.
Also read: Python vs. Anaconda: Physical features, predatory behaviours, and other key differences