Why do snakes shed their skin?

Ever felt like you wanted to crawl out of your skin? Snakes do — and unlike the rest of us after a long (and usually pointless) Monday morning meeting, they actually can. But why do snakes shed their skin? In this article we’ll look at the how and the why of snake shedding.

So, what is it? When a snake sheds its skin it’s a process known as “ecdysis,” taken from the Greek ekdusis, from ekduein meaning “put off,” from ek- meaning “out, off” and duein meaning “put.” Which is a very scientific and ancient Greek way of saying: “No thanks, I’d like a newer outfit.”

Snakes leave behind a dull and papery slough of skin that retains the intricate pattern of scales but not the colouration of the animal itself. It is essentially a ghostly snakesuit abandoned on the floor like yesterday’s socks.

Shedding skin is common throughout the natural world. Everything sheds skin to some degree, even humans, constantly losing tiny flakes of dead skin cells. Snakes, however, take this process to dramatic levels by producing an entirely new outer layer and removing the old one in a single piece. Because reptiles never do anything halfway.

The Kenyan sand boa (Gongylophis colubrinus) is an excellent example of a species that sheds regularly throughout its life, especially during periods of rapid growth.

But why do snakes shed their skin in the first place?

Snakes possess two primary layers of skin — the dermis and the epidermis. The dermis contains the colours and intricate patterns of the snake, while the epidermis forms the semi-transparent, keratin-toughened scales that act as protective armour. This outer keratinous layer forms a single piece, functioning as a sheath for the more delicate dermis underneath.

The problem is that this outer layer has very little flexibility. As the snake grows, the epidermis does not stretch sufficiently with it. This is the main reason snakes shed their skin, particularly while they are young and growing rapidly. Imagine trying to spend your teenage years wearing the same pair of jeans from primary school. Eventually, something has to give.

When a snake hatches (or is born, depending on species), its first shed usually occurs within a few days. As the snake prepares to shed, it develops a brand-new epidermis beneath the old one. During this process, a waxy secretion forms between the old and new layers. This secretion is absorbed by the old skin, making it softer and easier to remove.

This stage of the cycle is commonly referred to as “going into blue” because the snake’s spectacles — the transparent scales covering the eyes — become cloudy and bluish in appearance. For a few days, the snake essentially wanders around looking like it forgot its glasses.

Once the snake “drops out of blue,” meaning the fluid has been reabsorbed, it begins rubbing its snout and head against rough surfaces to split the old epidermis. The snake then slowly wriggles and slithers its way out of the old skin.

A freshly removed shed can sometimes measure up to 20% longer than the actual snake because the old skin stretches considerably before drying and becoming brittle. This has led many keepers to dramatically overestimate the size of their snakes after finding a shed and briefly convincing themselves they are secretly keeping an anaconda.

Unlike many geckos and lizards, snakes do not eat their shed skin. Species such as leopard geckos consume their shed to reclaim lost nutrients and minerals. Snakes, on the other hand, simply discard theirs and move on with the confidence of a celebrity leaving a hotel room.

The bamboo rat snake (Oreocryptophis porphyraceus) is another species known for producing beautifully intact sheds due to its smooth scales and humid natural environment.

The shedding cycle itself is actually a vulnerable and stressful time for a snake. Replacing an entire outer layer of skin is not a quick process, and during this period the snake becomes far more susceptible to predators. Their vision is impaired by the cloudy eye caps, and the old skin becomes tight and restrictive.

As a result, snakes instinctively hide themselves away during shedding, often seeking areas of higher humidity to help loosen and remove the old skin. Essentially, they become grumpy reclusive hermits until the skincare routine is complete.

Once a snake reaches adult size, shedding becomes less frequent and often ties into significant biological events. Brumating species may shed shortly after waking, reproductive animals may shed before laying eggs or giving live birth, and some species will shed again afterward.

Snakes may also shed to help remove parasites, repair damaged skin, or replace worn scales. Daily life for a snake can be surprisingly rough on the epidermis — especially when your preferred method of transportation is dragging yourself across rocks, branches and the occasional sharp bit of décor someone bought from a reptile shop because it “looked natural.”

So why do snakes shed their skin?

Snakes produce one of the most fascinating and instantly recognisable shedding processes in the animal kingdom. They use ecdysis not only to grow, but also to repair damage, remove parasites, maintain healthy scales and keep their bodies functioning properly. It is a remarkable biological adaptation — and also a useful reminder that sometimes a complete wardrobe change really does improve your outlook on life.