Adders

If you thought all snakes needed a warm climate to survive, you’d be mistaken. Adders are our only native snake and the only venomous reptile found in Scotland. They are timid and generally stay away from humans.

Adders are grey or reddish-brown in colour with dark zig-zag patterns running down the length of their backs.

Where do adders live?

Adders are only found in certain areas of Scotland. They inhabit quiet, open areas such as heathland, moorlands and woodland. Adders have even been spotted on beaches and amongst sand dunes during warmer weather.

What do adders eat?

Adders primarily eat small mammals like mice and voles but they will also hunt amphibians and small birds. They are active during the day and use their venomous bite to subdue their prey.

Do adders hibernate?

Adders hibernate throughout winter. From October to March, they nestle down in sheltered, dry spots such as disused burrows or hollow logs. It’s more common to see an adder in the warmer months in Scotland, perhaps basking in the sun on top of rocks.

When are baby adders born?

Adders mate in springtime after emerging from their winter hibernation. Unlike some snakes, female adders do not lay eggs. They instead give birth to up to 20 live young in late summer.

Will an adder attack me?

Adders are not aggressive snakes. They will only use their venom as a last resort if they feel threatened or cannot escape.

Most attacks happen when they are accidentally trodden on, picked up, or disturbed by a human or dog. If you come across an adder, keep a safe distance and leave them alone.

Keep dogs on leads and don’t let children get too close. Children and elderly people can be particularly vulnerable to adder venom.

Anyone who is bitten by an adder should stay calm and seek medical advice immediately.

My dog has been bitten by an adder, what should I do?

If your dog is bitten by an adder, or you suspect they have been, contact a vet as soon as possible.

If possible, carry your dog to slow the spread of the venom and pour cold water over the wound.

Signs to look out for include:

• Bite wounds, particularly on the head and legs.
• Swelling around the wound – you may be able to see puncture marks in the wound
• Lethargy.
• Difficulties breathing.
• Bleeding or bruising.
• Lameness or appearing wobbly when walking.
• Appearing nervous or in pain.
• Fever.
• Increased heart rate.
• Drooling or vomiting.

Adders are most active from April to July. If you are walking where adders are known to inhabit, keep your dog away from long grass or undergrowth, especially on hot days. Attaching a bell to your dog’s collar can warn adders to take cover and help prevent injury.

Confusing adders for other snakes

Many people will never have seen a wild snake in Scotland. It is therefore easy to confuse adders for another species. These include smooth snakes, grass snakes and slow worms.

• Smooth snakes are mostly located in the southwest of England so it’s unlikely that you will encounter one in Scotland. They do look similar to adders but smooth snakes don’t have the distinctive zig-zag pattern along their backs.
• Grass snakes also prefer habitats south of the border although they have been recorded here in Scotland. They can be distinguished from adders by their greenish-grey colour, yellow and black collar, pale belly and dark markings down either side.
• Slow worms are often mistaken for adders but they are actually a type of legless lizard. They are usually found amongst piles of wood, stones or compost. Males are paler in colour compared to females and sometimes have blue spots. Females have dark sides and a dark stripe down their back.

What do I do if I come across a snake that looks out of place?

If you see a different species of snake which could be an escaped or abandoned pet, call our helpline on 03000 999 999 for advice and remain a safe distance away.

Please contact us for support if you have a pet snake you can no longer care for. It is an offense to release any non-native animal into the wild, or to allow their escape from captivity.

Common problems

Predators

Adders are mainly preyed on by raptors and some members of the corvid family. Other predators include mammals such as badgers, foxes and feral cats.

Population decline

There is evidence of long-term population decline of the species across the UK. However, the last survey of adders in Scotland was in the early 1990s so the situation here is less clear.

Adders are extremely sensitive to changes in their environment. Deforestation, changes in their habitat, and climate change are considered to be the main factors in their decline in numbers.