by Erin Byers

Created on: September 26, 2008   Last Updated: September 30, 2008

Ponder this question, "Do snakes have skin or scales?" References to "snake skin" are commonplace, yet snakes appear scaly. In fact, snakes have both skin and scales! Scales essentially grow out of the snake's skin, covering their entire body. Scales are what we see when we look at a snake, and what gives each species their indentifying features. But, what purpose do they serve on a snake? Scales are essential and play multiple roles in snake's lives.

Scales protect the snake's skin, assist in locomotion, help the body retain moisture, and can play an important role in camouflaging. Snakes are covered from head to tail with scales in varying shapes and sizes. Scales consist of a substance called keratin, which is the same substance that human hair and nails consist of. Scales on the underside of the snake, called ventral scales, are large and form a single row. These scales appear to form "half-bands" on the snake's belly. Also known as gastroteges or scutes, these are usually the smoothest. This feature helps to reduce friction as the snake moves.

Dorsal scales, or the scales on the upper part of the body, are the ones most visible to us and predators. The shapes, colors, and characteristics of these scales vary with each species. There are two main categories identifying snake scales. "Keeled" scales are ones that have a ridge that runs the length of the scale. These types of scales give the snake a rougher look and feel. Rattlesnakes, water snakes, and garter snakes all have keeled dorsal scales. Smooth scales are just that; they lack a ridge.

Dorsal and ventral scales are what cover the majority of a snake's body. There are also special head scales and tail scales, which are just as important, yet can get quite in depth. There are even scales that cover the snake's eye! Snakes lack eyelids, therefore, a clear scale called the brille, is what protects the eye from dirt and debris. This scale sheds along with the rest of the snake's body during a process called ecdysis, or moulting.

Snakes are born with a set number of scales. As the snake grows, they do not acquire new scales nor do they lose scales. Ecdysis, or shedding, is necessary for the snake to grow, and they do this until the day they die. During this process, snakes do not actually shed their skin, but rather, just the outer layer of their scales. Essentially, a fluid builds up beneath the outer layer, allowing the snake to emerge from the old skin. Young snakes can shed monthly, while adults may only shed a couple times a year.

There are some myths that surround the snake and their skin and scales. One of the most common is that snakes are slimy. This is false, as snakes have rather dry skin. Since snakes are cold-blooded, they may feel cool to our 98.6 degree hands, but they are in no way slimy. Another misconception is that one can tell how old a rattlesnake is by how many rattles are on its tail. Rattlesnakes gain a new rattle each time they shed; therefore they can gain more than one rattle each year, depending on how many times they shed. It is also possible that rattlesnakes can have pieces of their rattle break off. Unlike determining a tree's age, this method is unreliable for determining the age of a snake.

Counting a rattlesnake's rattles is not only unreliable for determining age, it is also not recommended! Even a dead rattlesnake's venom can be dangerous. It is best to leave handling of snakes to professionals!

Everything in nature has a purpose. What appears to be a simple feature, such as scales, actually serves in what seems to be some complex functions for the survival of a snake.

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