Do snakes ever blink?

10 August, 2008

Question: Do snakes ever blink? We stared at the snake in the Melbourne Museum for ages – it didn’t blink once. It didn’t move either, but the staff at the museum assured us it was alive.

Answer: I’m afraid you picked the wrong animal to have a staring competition with.

Yellow-faced Whip Snake, Demansia psammophis

A Yellow-faced Whip Snake (Demansia psammophis) shedding its skin.
Photographer: Peter Robertson / Source: Museum Victoria

Snakes have no eyelids. Each eye is covered with a single clear eye scale. These eye scales protect the eyes from injury and prevent the eyes from drying out.

Snakes are therefore unable to close their eyes – they can’t blink and they must sleep with their eyes open. The snake you observed at the Melbourne Museum may therefore have been asleep.

A snake’s eye scales are part of its skin. This means that when a snake sheds its skin, it must also shed its eye scales. Prior to shedding, a snake’s skin becomes dull and the eye scales become cloudy or opaque. This is because snakes secrete a milky fluid between the old skin and the new skin before they shed.

Mitchell's Short-tailed Snake, Suta nigriceps

Mitchell's Short-tailed Snake (Suta nigriceps) shedding its skin.
Photographer: Peter Robertson / Source: Museum Victoria

When they’re ready to shed, snakes rub their snouts against something until their old skin splits. They then work to peel the skin back from their lips to their tails, turning it inside out like a stocking as they do so. Snakes tend to shed their entire skin in one piece and the eye scales are very obvious on a shed skin.

A Death Adder shed skin

The shed skin of a Death Adder showing the eye scales.
Photographer: Alan Henderson / Source: Minibeast Wildlife

Comments (6)

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Jim Mason 9 November, 2009 08:41
Please assist me with information. I am aware snakes can be identified by counting scales on the skin. 15, 17, 19 etc sppit anal etc. Please assist me or direct me ro spcific information - tiger copperhead brown etc. I have tried google but have failed.
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Discovery Centre 10 November, 2009 11:40

Thanks for your question Jim.  We have contacted the Senior Curator of Terrestrial Vertebrates and asked for her expert opinion.  She advised that there is a great book by Cogger titled 'Reptiles and Amphibians of Australia'  There is a description of how to count scales and other morhpological features in the beginning of this book.  The Discovery Centre has a copy of this book in the library and you would be most welcome to come in and access it.

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toshit 13 August, 2010 02:13
why does snake shed their skin?? and after how much times do they do this???
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Discovery Centre 14 August, 2010 12:29

Snakes shed the outer layer of their skin in a single piece, unlike mammals who are continuously shedding skin cells as they grow. The hardened outer layer of snake skin is quite tough to withstand abrasion endured while moving, resisting the attacks of external parasites and preventing water loss through dehydration and must be shed to allow the snake to physically grow larger. The amount of times a snake sheds its skin varies due to several factors including the snake’s age, the snake breed and also environmental factors such as how much food is about.

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keiran 23 February, 2011 04:04
i was just wondering if sheding affects the snakes ability to see and catch there prey
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Discovery Centre 25 February, 2011 11:56

Hi Keiran,

When a snake sheds its scales it actually sheds a spectacle off its eye. This means that when it is looking out at the world just before shedding it would probably be looking around through frosted glasses. You can see a snakes eyes become ‘cloudy’ – this is the spectacle detaching from the eye so a new one can form underneath. Snakes, as you may imagine become nervous during this period with reduced eye sight and may ‘strike out’ in defence at movement around them. Here at the museum we leave them alone over this time and it isn’t too long before they slough their old scales off and are hungry to feed again. We always check to ensure that important spectacle is shed cleaning off the snake, this can be easily check by looking at the old sloughed and seeing if you can see where the ‘eye scale’ is.

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