Scrutinizing Splendid Snake Senses: How Do Snakes See?

Devangana Rathore
Mar 07, 2023 By Devangana Rathore
Originally Published on Nov 01, 2021
Edited by Lara Simpson
Body of green tree python Morelia viridis

Imagine you're a snake; you don't have any ears, and you can't blink, even if your eyes are enormous and adequately developed.

However, many snakes possess infrared vision. Consider it a sixth sense or evolution's present to these cold-blooded reptiles.

Infrared rays (also known as heat vision), which have greater wavelengths than visible light, confirmed the existence of warm-blooded prey in three dimensions, allowing snakes to target their strikes better.

Boids and pit vipers, the two snake species with this ability, contain heat-sensitive membranes that detect temperature changes between moving prey like a running mouse. Snakes can live anywhere from four to more than 25 years, depending on the species.

So even in complete darkness, several snake species can locate and grab prey with incredible accuracy. If you like reading about snakes and slithering creatures, then you should absolutely take a look at when do snakes hibernate and what do snake eggs look like.

Do snakes have eyes?

Most snakes can't see well, excluding a few animals that have evolved to daytime hunting. They can perceive forms but not details in general. Snakes have eyes that are similar to those of most terrestrial animals.

Snakes had to 'reinvent their eyes,' according to most scientists. Their optics are almost identical to those of the remainder of the tetrapods. Snakes get an ocular scale called the spectacle renewed each time they lose their skin, but other terrestrial vertebrates possess eyelids to protect their eyes.

While most species contain rods and cones in their retinas, the snake's sight will vary depending on its lifestyle. For example, subterranean snakes have basic eyes with mere rods that allow them to discriminate between daylight and darkness.

Do snakes see color?

The study discovered snakes are dichromatic, indicating they can recognize two primary colors, blue and green.

In addition, many snakes have developed a sensitivity to UV light and their color vision, allowing them to observe in reduced situations.

Can snakes see in the dark?

Snakes have protein receptors that are stimulated by heat from the bodies of the prey, allowing them to 'see' in the dark. Pit organs are found in pythons, vipers, and boas, and they contain a membrane that detects infrared radiation of warm bodies up to one meter away.

The pit organs allow snakes to scan a picture of their attacker or prey in the dark, similar to how an infrared camera does, providing them with a unique sensation.

A study released online in Nature by US scientists has demonstrated how this occurs at the molecular level. An ion channel called  TRPA1, an infrared receptor found in nerve cells in the pit organ, perceives infrared radiation as heat instead of illumination, validating notions of pit-organ function long-held by behavioral ecologists.

The TRPA1 channels, often known as wasabi receptors, are also found inside the skulls of mammals. Thus, despite possessing fewer pits than pythons, pit vipers' pits are more sensitive than pythons.

The scientists reasoned that comparing the trigeminal and dorsal root ganglia would be useful to zero in on the organ's molecular heat sensor. The latter provide sensory information to the brain from the neck down and are less likely to create proteins exclusively needed by pit organs to detect heat.

The researchers examined the various RNAs produced by each type of neuron, which indicate which genes are active and creating proteins.

How do snakes see humans?

Snakes have a membrane in their pit organs that can detect infrared rays from warm bodies up to one meter away. The pit organ comprises the snake's somatosensory cortex, which detects touch, heat, and pain.

Although, still, it does not pick up signals from the optics, indicating that snakes' eyes' are infrared by sensing heat rather than photons of light. When a minimum temperature is achieved, TRPA1 channels open, allowing ions to pass into the nerve cells and producing an electrical signal.

The antenna membrane is suspended in a hollow bone chamber, allowing for rapid heat loss and increasing the temperature differential between warm-blooded animals and anything else. According to the researchers, Rattlesnake TRPA1 is activated by temperatures more than 82.4 F (28 C), which is the temperature a snake would 'sense' from a rodent or squirrel about a meter away.

Although discovering the sensors is a significant contribution, cell biologists and physiologists believe more in the pit-organ tale.

How do snakes see two ways?

Even with its eyes shut, a snake could recognize a warm-blooded animal.

This is because its infrared sensors are basically receptor cells in the pit organ. According to the research, they come in various shapes and sizes, potentially to 'gaze' at different infrared wavelengths.

In addition, whereas the top jaw of a human is joined to the skull and hence incapable of moving, a snake's higher jaw is joined to its braincase by ligaments, muscles, and tendons, allowing it to move from the front to back or side to side.

Animals that hunt at nighttime have lenses that allow more Ultraviolet rays, making it easier for them to notice in the darkness. The scientists found that the reptiles that feed during the day have lenses in the pupils that exclude ultraviolet light, allowing them to view clearly in bright situations.

Species that hunt at night have lenses that allow more UV radiation, making it easier for them to eye in the dark.

Can snakes see well?

The optics of these reptiles are small and underdeveloped. Snakes have notoriously poor eyesight due to their evolutionary past as burrowers who lived in the dark without much need for vision.

The study's findings were reported in the journal Molecular Biology and Evolution. This is why, to gain a sense of their surroundings, they constantly stick out their tongues. However, the creatures may be able to improve their vision in an emergency.

Different snakes can detect other wavelengths in addition to a visual glow. Pit vipers and some pythonomorphs (boas and pythons) have the ability to sense infrared radiation and look at the thermic signal around them. Because they can detect their own body heat, this is particularly effective to detect prey in low light circumstances.

As you can observe, snakes recognize the world in a totally different way than humans. However, these various reptiles have different and diversified adaptations to comprehend their surroundings. We hope that by reading this article, you've been able to learn about the fascinating world of snakes.


Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for how do snakes see, then why not take a look at how to identify a baby copperhead snake or vine snake facts.

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Written by Devangana Rathore

Bachelor of Arts specializing in English Language, Master of Philosophy

Devangana Rathore picture

Devangana RathoreBachelor of Arts specializing in English Language, Master of Philosophy

Devangana is a highly accomplished content writer and a deep thinker with a Master's degree in Philosophy from Trinity College, Dublin. With a wealth of experience in copywriting, she has worked with The Career Coach in Dublin and is constantly looking to enhance her skills through online courses from some of the world's leading universities. Devangana has a strong background in computer science and is also an accomplished editor and social media manager. Her leadership skills were honed during her time as the literacy society president and student president at the University of Delhi.

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