Snakes have no limbs, which will make you wonder how they manage to move around when the need arises. Snakes move in a variety of ways, and some snakes move surprisingly quickly. So, how does this happen?
Snakes move around by using a combination of muscles and scales. Movement methods include the ‘S-shaped serpentine’ and the ‘rectilinear creeping method.’ These techniques are used by species of snakes, depending on the kinds of landscapes that they need to cross.
Studying snake movement not only gives us information about the health and abilities of snakes, but also can teach us new ways to navigate the world. Let’s learn about the science of how snakes move.
Science Behind Snake Movement
Given that snakes don’t have any legs, they need to use other parts of their body to move about in the wild. The body parts that they use are as follows:
Ribs and Muscles
Snakes have incredibly flexible bodies. Depending on the type of snake, their long spine can have hundreds of ribs attached to it. Each rib is connected to strong muscles that the snake can use to push itself along.
Another factor in snake movement is their belly scales. Snakes can move on all kinds of surfaces, apparently defying gravity as they climb up walls.
The snake’s scales give them the ability to grip onto a textured vertical surface. They may not have hands, but these snakes can hold on tight.
According to Arizona State University, snakes can shift their belly scales to actively alter how much friction they have with a surface.
They compared the ability of conscious and unconscious snakes to remain balanced on a flexible pillar. Where the unconscious snakes fell off, the conscious snakes were able to double their friction coefficient and hold on.
Snake Movement Patterns
It’s easy to assume that all snakes move in the same way. In animated movies, they always seem to use the same twisting, waving motion. It’s the pattern that we think of when we use the word “snaking”.
However, there are actually 4 main types of snake movement. Let’s take a look at the different patterns.
When you imagine a snake, you likely envision an animal moving in a wavy motion. The snake appears to form the shape of the letter S on the ground as it travels. This is the serpentine movement pattern. This kind of motion is also called lateral undulation, or sometimes undulatory locomotion.
Snakes moving in this way will push off of surfaces to get themselves moving. This can be any bump on an object, such as a tree or a rock, or a dent in the ground.
As such, the serpentine method is not effective for moving over smooth surfaces, such as glass, but it works very well on a rough forest floor. The snake pushes against the irregularities with its scales and thrusts itself forward in a curving shape.
This is the most common form of snake movement. Most land and water snakes move in this way. Of all forms of snake movement, the serpentine movement allows the snake to move extremely fast.
The concertina technique is often thought of as an “accordion” kind of motion. This is because the snake contracts and expands its body similar to an accordion.
A snake moving in this way braces the back end of its body, and then it pushes its head forward, twisting and extending the front part of its body upwards and outwards. Next, the snake lowers the front part of its body to the ground, straightens itself out, and pulls its back end along.
While other snake movement methods work great on flat, horizontal surfaces, the concertina motion is how snakes manage to climb. The grip of its scales when it braces itself is strong enough to hold onto a vertical surface.
Sidewinding snakes appear to throw themselves along the ground. First, they throw their head forward. Then, the rest of its body is thrown along behind it.
This kind of snake movement is effective for helping the snake move across unstable or slippery surfaces, such as mud or desert sand.
You will see that tracks from these snakes are disconnected, like long, skinny footprints in the sand, rather than one connected trail. Most of the snake’s body is off of the ground when it sidewinds.
The word “creeping” comes to mind while watching a snake move with the rectilinear method. These snakes do not move from side to side, but straight forward. Many people call this technique “the Caterpillar method” because of its similarity to those insects and how they travel.
In this rippling kind of movement, scales on the snake’s belly grip the ground firmly, while the other scales are used to push the snake forward. The snake’s body curves in an up-and-down motion, rather than the typical side-to-side.
The rectilinear method is less common than other snake movements. As such, it’s only in recent years that studies have been conducted to better understand this method of travel for snakes.
Snakes that use the rectilinear method have specialized muscles to move their belly skin. This movement allows snakes to enter the narrow burrows of smaller prey animals, where there isn’t enough room to wave from side to side.
Snakes that move in this way are dramatically slower than other snakes, but they have the unusual ability to move in a straight line.
Differences in Snake Movement
Why do some snakes use one kind of movement, while others use another?
These movements vary among snake species across the world. There are many factors that lead to certain species picking their own unique approach to travel, but their size and the kind of terrain they move across plays a huge role. Let’s explore these main factors.
Most snakes alternate between the ribs and belly scales they use to push their body along. They will first push on one side, and then push on the other. This creates that common side-to-side motion we call serpentine.
Larger snakes, however, may push with both sides of their belly scales and ribs at the same time. This creates a more direct, straightforward movement.
As a result, you are more likely to see a larger, heavier snake move in a rectilinear fashion than a smaller snake. An example of a heavy snake that uses this method is the Burmese python, which appears to glide along the ground as it lifts each part of its body in turn.
Smaller snakes are more likely to move in a serpentine way. After all, they have less strength and body mass to leverage.
Climbing snakes and burrowing snakes are more likely to move like an accordion than in a side-to-side motion.
These snakes stretch out the front end of their bodies first, and then they pull the rear part forward to join it. This lets them move along vertical surfaces and in a straight direction – useful for trying to go up a tree or down into the earth. For example, the green tree python uses the concertina method to tuck itself cleverly in the branches.
Desert snakes, such as the aptly-named sidewinder rattlesnake, are more likely to use the sidewinding motion. This is partially because the motion helps them move further across a sandy surface without much to grip onto. Sidewinding also keeps the snake from putting down too much weight at a time, sinking into the sand.
Other desert snakes, like the rattlesnake, prefer this method thanks to one main factor: it minimizes the amount of time their body touches the hot desert floor. Desert sands can be scorching, even to reptiles.
Water snakes heavily favor the serpentine movement. Every time the snake contracts its body, thrusting itself from side to side in a curving motion, its body pushes against the water around it. This propels the snake forward quickly and decisively.
A notable water snake that uses the serpentine method is the anaconda, the heaviest snake in the world. This snake uses serpentine motions to propel itself through South American rivers and swamps.
Snake speeds vary greatly across species. The fastest known snake, the black mamba, has been recorded at moving along up to twelve miles per hour! That’s more than enough to chase down most prey (and even humans).
At the other end of the speed scale, the rosy boa cannot achieve enough speed to pursue its prey like other snakes. Instead, this snake lies in ambush, striking when food comes within reach.
There are a few snakes that defy all the expectations set by the behavior of other snakes. This merits their own category.
Flying snakes are found in Southeast Asia and Sri Lanka. These snakes do not actually fly upward as birds do, but they are excellent gliders.
They hang from high tree branches, swinging themselves far out into the air. Once airborne, the snake widens its ribs and flattens out its body. Then the snake performs a serpentine side-to-side motion, which helps to maintain its hang-time as it glides.
What Can Movement Reveal About a Snake’s Health?
Snakes tend to move slowly, so it can be difficult to tell when something is off about their movement or other behavior.
Additionally, different snake species have different activity levels, so it is hard to generalize across the board. Nonetheless, these main signs will help guide your assessment:
Healthy snakes have good muscle tone and scales that grip well. When you pick up these snakes, they are able to hold on to your skin.
They’ll also move around on their own as you pick them up, with strong, decisive motions.
Righting Its Position
If you flip a healthy snake upside down in the air, it will try to right itself by slithering up over your hand.
A sick snake, on the other hand, will usually remain limp when you pick it up. If you flip a sick snake upside down, it may not attempt to right itself.
Unhealthy snakes also tend to adopt a new, stiff posture, which can make the snake look like it is constantly holding its head up to look at the sky, instead of keeping its head near the ground.
If you handle your snake regularly, you will become used to how its ribs and scales move when it’s healthy. If something suddenly changes about your snake’s movement or activity level, be sure to take them to a reptile veterinarian.
What We Can Learn from How Snakes Move?
Researchers at Ibaraki University in Japan took a special interest in snake movement. By studying the creeping rectilinear movement, they figured out how to replicate this motion in robotics.
These engineers created a snake-like robot. Not only can it move without legs, but it can also move in a straight line and enter small, confined spaces.
This creation is revolutionary. A robot that can easily enter small spaces could prove essential for search and rescue efforts after natural disasters.
Snake-like robots do not have legs that can be caught in holes or debris, allowing them to navigate rough and uneven terrain. These robots could also climb vertical surfaces in similar ways to living snakes, expanding the reach to new heights (literally and figuratively).
The way snakes move is, therefore, not only important for snakes, but also for humans. It proves us with a whole new way to explore the world.