I’m not a snake and I’ve not had too much to drink


Full Screen Image – Slow Worm, Glen Convinth, Highland Scotland ©Nick Sidle

After my post on the discovery that the underside of at least one species of snake has a lubricating film on the scales in which I said Scotland has only one species of snake regarded as resident, the European Adder, I was asked ‘what about the Slow Worm?’ True, it does look more like a snake than anything else and it most certainly is resident in Scotland, including in the Highlands in the North, but it is not actually a snake at all, or a worm for that matter. The Slow Worm is actually a lizard without any legs, legless as it is usually described, but in no way connected to alcohol.

Boloria euphrosyne

Full Screen Image – Slow Worm, Polmaily, Glen Urquhart, Highland Scotland ©Nick Sidle

They are smaller than snakes and have what is called as a semifossorial lifestyle, which is a complicated way of saying they spend a lot of time not strictly burrowing into the earth like a mole which is fossorial, but going a bit in that direction by hiding under things, hence semifossorial. The key features that confirm they are not snakes (and are lizards) include:

Having eyelids and blinking

Boloria euphrosyne

Full Screen Image – Slow Worm, Polmaily, Glen Urquhart, Highland Scotland ©Nick Sidle

Having visible ears

Shedding their skin one area at a time, not all in one go

Being able to break off their tail to escape a predator

They are also no threat to anyone, like almost all lizards they do not have a venomous bite (a few do such as the Gila Monster but the only ones I know are from South America, not even Europe, and most certainly do not include the Common Lizard found in Scotland). It should also be remembered that the majority of snakes are not poisonous, but to be fair the Adder is and should be treated with respect and caution.

Slow worms can be very long lived with estimates of up to thirty years in the wild and records of 54 years in captivity. One very important threat to them is the domestic cat which kills them almost indiscriminately, whether this is because the cat also makes the mistake of thinking they are a small snake and a threat that should be dealt with or whether they are too tempting prey to resist is an open question.

In Scotland and the rest of the UK, Slow Worms are decreasing in number and are a protected species under the Wildlife and Countryside Act meaning it is illegal to take, harm or disturb them.


Scotland’s Reptiles and Amphibians Gallery

Glen Convinth

Slow Worm – Anguis fragilis