Adder, grass snake or smooth snake - how to tell them apart

Adders are the most dangerous as they are the only venomous one out of the three.

You are most likely to see these native snakes in the wild, but there is a chance of them making their way into your garden during the warmer months, the RSPCA said.

The animal charity added: "If you see a native British snake in your garden or the wild, please leave them undisturbed.

"Contact us only if the snake is sick or injured."

So how do you tell the difference between an adder and a grass or smooth snake?

The difference between an adder, grass snake and smooth snake 

Adder

Adders have a red eyes and a distinctive zig-zag pattern down their backs. (Image: Neil Bowman/Getty Images)

According to the RSPCA, an adder has a "distinctive zig-zag pattern down his/her back, with red eyes and a vertical pupil". 

While they can grow up to around 70cm.

The RSPCA added: "They're the only venomous species of snake in the UK!"

They are located in various locations across the UK, but the animal charity said their numbers were in decline.

Grass snake

A grass snake is olive green in colour with large green eyes and round pupils. (Image: Getty Images)

In comparison, grass snakes are usually an "olive green colour, with large eyes and round pupils". 

Grass snakes can grow to be over a meter long.

The RSPCA added: "They have a distinct collar behind their heads and are also the only native snake species to lay eggs."

They like to use compost heaps to lay their eggs, which are soft and leathery.

Smooth snake

The smooth snake is the rarest snake in the UK. (Image: Getty Images)

The smooth snake is the least widespread across the UK, according to the RSPCA, and is localised to the south of England, mainly found in heath habitats.

It is the smallest species, growing to only around 55cm in length.

The RSPCA added: "They're typically a greyish brown in colour, have a dark stripe down the side of their face, a heart-shaped pattern on their head and a pattern of spots and bars along their back!"

Is it a slow worm?

Sometimes other reptiles can be seen sneaking around the garden and are mistaken for snakes.

The most common reptile mistaken for a snake is the slow-worm.

Native wild animals in the UK

The RSPCA says: "Slow-worms (Anguis fragilis) are actually legless lizards and not snakes!

"They can reach around 45cm and unlike snakes, they have eyelids.

"They are typically shades of grey or brown, and some males have blue spots."

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What to do if you find a snake in your garden

If you stumble across a native British snake in your garden or in the wild, the RSPCA says to "please leave them undisturbed".

If the snake appears to be injured or wounded, contact the animal charity.

The RSPCA added: "If you find a non-native species of snake, please keep your distance and call our advice line on 0300 1234 999."