Download PDF

Bookmark added to your notes.
View Notes

One of the most feared creatures in the world is the snake. Snakes are reptiles with no wings and limbs. The slender cylindrical body starts with a head and ends with a tapering tail. There are at least 3400 types of snakes recorded by zoologists across the world.

Among them, only 600 are venomous but all are carnivorous. It can live on land or in water considering the species. Some snakes can do both. Some inject their venom and kill their prey before eating them. Some attacks viciously and maim the prey, strangulate and eat them. Let us find out more information about snakes in detail.

Classification of Snakes

Snakes originated from terrestrial lizards in the Middle Jurassic era (174.1 to 163.5 million years back). The oldest discovered snake fossil dates back to 167 million years. The scientific name of a snake is determined based on the characteristics and other factors. Snakes fall under the suborder Serpentes which is why they are commonly called serpents. As mentioned earlier, they are reptiles but with no wings and limbs. All they have is a slender elongated cylindrical body and a tail. This species falls under the same order Squamata of lizards. Hence, the classification of a lizard represents a snake. Due to the evolutionary process, the snakes have lost their limbs and developed various physiological features.

They have undergone simplification and structural reduction. They have also increased a special feature and lost some. Remember that not all limbless reptiles are snakes. There are burrowing lizards that also have lost their limbs due to evolution. The only difference between such lizards and snakes is that the former have eyelids. Snakes do not have eyelids and tend to give a deadly stare. One of the interesting snake characteristics is that it has lost its urinary bladder. Due to its slender body and cylindrical shape, all the organs are elongated and sleek. In fact, the left organs are greatly reduced in comparison to the right organs.

Characteristics of Snakes

As mentioned earlier, snakes are reptiles with no limbs. Some of the species have vestigial traces of hind limbs that show the perfect evidence of evolution. It tells us that they evolved from limbed lizards back in the Jurassic era.

The snake characteristics also tell us that they have horny scales all over the body. The scales and skin are well clasped. They shed their skin a few times a year. A shed skin shows the configuration of the scales perfectly. On the other hand, the number of vertebral discs has increased. It also has developed an organ that secretes venom. It also has developed the tracheal lung as a breathing system.

Another remarkable feature of snakes is that the organs are not oriented bilaterally rather they are placed side by side. The jaws of the snakes are not fixed but are loose so that they can gobble prey larger than their head. The bones in the head also support in gobbling prey. The teeth are backwards curved and are fused with the head bones. They do not have any ear, as well as, movable eyelids. It means that snakes are unable to receive any sound waves. It can perceive sound waves of frequency ranging from 100 Hz to 700 Hz with its skull bones.

It has a remarkable chemosensory organ developed on the roof of its mouth that receives chemical stimuli from the bifurcated tongue. You will observe that the tongue comes out, lashes a few times, and then enter the mouth to provide the chemosensory information gathered. These are the snake characteristics that distinguish it from the other reptiles. Snakes do not have any vocal cord or larynx to produce sounds but they can hiss.

Movement of Snakes

Different types of snakes move in different ways. As per the zoologists, there are four kinds of movements found in the serpentine family.

Serpentine Method

This is the way a snake moves generally on land. They are limbless and use their muscles to bend and un-bend their bodies to create a serpentine motion we are familiar with. You will be surprised that they use the scales present in the lower part of the longitudinal body that touches the ground. In this type of movement, snakes will not overcome any hurdle rather try to push off the way and keep going. This is how many types of snakes move on land.

Concertina Method

This is quite an unconventional movement style when it comes to snakes. It might not be the best way to move in an open space to catch prey or evade predators but is very useful for moving in tight spaces. In this method, a snake holds the back portion tight while extends the front portion using the back as a pivot. The front portion is then straightened to pull the un-braced back portion forward.

Side Winding

This is also a difficult way to move in open grounds but very effective when the surface is slippery or loose. You might have seen this movement among snakes in the desert areas. They do not move forward rather make a diagonal displacement by bending and unbending their bodies. The movement method depends on where do snakes live. This motion is ideal for snakes living in muddy areas, swamps, and deserts.

Rectilinear Method

This is a slow movement but very useful to proceed closer to anything suspicious or prey. Snakes can make a soundless movement using this front-facing slow non-bending motion by just using contraction and relaxation of the muscles. The belly scales grip the surface and do the major work.

The Life Cycle of a Snake

As the snake lower classifications suggest, it is a reptile and will lay eggs. Hence, life begins from an egg.


After the mating part of the female and male snakes is done, the female tends to store the sperm collected from the male donor. The sperm can exist naturally in the oviduct for at least a month or two. Once the fertilization is done, eggs develop inside the ovary of a female. She lays leathery 10-15 eggs at a time. The shells are not hard like birds. She guards the eggs with all her might until they start hatching. The incubation time varies from one species to the other. In fact, it also depends on the environmental conditions.

Young Snakes

The eggs hatch and young snakes come out. It happens when the environment provides a sufficient amount of heat. The small snakes break the shells with their soft teeth. The game or survival begins. The female snake will not feed the baby snakes. They have to find food almost on their own. They live on small rodents, reptiles, etc. They shed skin at least 4 times during their growing stage. This helps them to get a new skin and to get rid of parasites residing on their skin.

Adult Snake

It depends on the species when a snake will become an adult. When the adult reaches its age, it sheds skin two times a year. They hunt and feed on prey to survive and wait to mate with the opposite gender. In this way, the life cycle goes on.

Snakes and Venom

We know how many types of snakes are present in the animal kingdom in a rough way. Marine snakes are diverse and more venomous than land snakes. When it comes to venom, snakes are harvested to extract venom and make medicines. Venom is produced in a sac in the buccal cavity. This sac is connected to the front canine teeth via a duct. An adult snake can control the amount of venom it wants to inject into prey or a predator. A baby snake takes to develop this capability and tends to inject more than required venom causing fatalities.

It has been found that more than 40% of the bites inflicted by the snakes are defensive in nature. They do not want to waste venom on something bigger or they cannot eat. In some cases, they bite but no venom is injected. It is done as a threatening sign to an approaching animal. One of the most famous species is the rattlesnake. It has a bad reputation when it comes to snake venom. You will be astonished to know that it is a shay snake and tends to retreat. It attacks only when molested or provoked. The same stands true for Indian cobra. The scientific name of the snake is Naja naja.

Humans and Snakes

Snakes have been a part and parcel of human mythology for millenniums. Snakes are interpreted as vicious and traitors in every fable or folklore. This actually harms the snakes way more than the changing environment. People do not even try to learn the nature of snakes and rather want to get rid of them even if a species is harmless. There are different types of snakes where most of which are non-venomous.

Humans have died due to snake bite. It happens only when a snake is threatened by the unwanted presence of another animal. The loss of life and livestock due to snakebites made us think that snakes are nothing but our enemies. Even Satan is also interpreted as a snake in heaven’s garden that provoked Adam and Eve to eat the fruit.

Only 300 species are recorded as venomous. This small percentage of the snakes makes the entire order infamous. In fact, half of this percentage inflicts a bite that can be lethal to humans. Despite the fact, nearly 140,000 cases are recorded across the world and the majority of these cases occur in Southeast Asia. It happens because of improper medical facilities. If you consider the statistics of the USA, less than 8000 cases occur annually and only 10 people die. People die more due to lightning strikes and bee stings in the USA rather than snake bites. The average snake lifespan is 2 to 30 years depending on the species.

Where Do Snakes Live?

You will find this reptile almost everywhere in the world. Just leave Antarctica from finding snakes. It is a cold-blooded animal hence it is hard to survive in harsh cold weather. It is the only climate that snakes are unable to tolerate and survive. The question of where do snakes live can be easily summarized now. You will find them in freshwater sources, land, seas, marshes, and oceans. They are found in tropical forests, deserts, prairies, and even under old buildings. They find a hole and slither in to stay safe from the threatening world outside. One thing to know about a snake is that it always chooses a secluded area with a minimum disturbance. The different types of snakes have different habitats considering their adaptations.

FAQ (Frequently Asked Questions)

Q1. How Can a Snake Hear?

As the physiological characteristics of the snake lower classifications suggest, they do not have ears. They use their jawbone and skull to absorb vibrations. These sound vibrations are then transmitted to the inner ear.

Q2. How Non-venomous Snake Kill?

Most of the non-venomous snakes give a strong bite and strangle their prey until they suffocate and succumb to the injuries. They keep on constricting the muscles and even break the bones of prey inside.

Q3. Which is the Oldest Snake?

As per the documentation done by BBC, the highest snake lifespan has been recorded for a ball python that lived for more than 62 years. Pythons are also considered as the oldest and existing species of snakes originating on earth 48 million years ago.

Q4. Why Do Snakes Shed Skin?

Snakes shed skin to get a new one when it grows. It also helps them to ward off parasites and infections. A young snake does it 4 times whereas an adult does it 2 times annually.