Our native reptiles include three lizards and three snakes; Sand lizard (Lacerta agilis), Common lizard (Zootoca vivipara), Slow worm (Anguis fragilis), Grass snake (Natrix natrix), Smooth snake (Coronella austriaca), and Adder (Vipera berus).

During a recent visit to Collyweston Great Wood and Eastern Hornstocks SSSI & NNR in Northamptonshire, UES found 3 of our 6 native reptile species; Slow worm, Grass snake and Adder.

Slow worm

Slow worms are often found in gardens and are widespread throughout the British Isles. Slow worms are lizards, though they are often mistaken for snakes. Unlike snakes they have eyelids, a flat forked tongue and can drop their tail to escape from a predator.

Grass snake

Grass snakes are found throughout England andWales. This is the UK’s longest snake, growing to well over a metre in length. Feeding primarily on fish and amphibians, grass snakes can occasionally venture into garden ponds in the summer months, particularly in rural or semi-rural parts of the south.

Grass snakes are non-venomous and are extremely timid, moving off quickly when disturbed. If cornered they can feign death, and if handled frequently, produce a foul-smelling excretion.


The adder is the most northerly member of the Viper family and is found throughout Britain right up to the north of Scotland. In Scandinavia its range extends into the Arctic Circle. It is not, however, found in Ireland. Adders like open habitats such as heathland, moorland, open woodland and sea cliffs, and rarely stray into gardens.

The adder is the UK’s only venomous snake. However, their secretive nature and camouflaged markings mean they often go unnoticed.

Slow worms, grass snakes and adders are protected by law in Great Britain against being deliberately killed, injured or sold/traded in any way.