Natrix helvetica

Note: Research published in August 2017 proposed a change to the classification of European grass snakes. According to this research, the scientific name of native British grass snakes becomes Natrix helvetica. The research showed that Western European grass snakes, including the UK ones, were significantly different from snakes east of the River Rhine, and so merited full species status.

Reference: Kindler, C, Chèvre, M, Ursenbacher, S, Böhme, W, Hille, A, Jablonski, D, Vamberger, M & Fritz, U (2017): Hybridization patterns in two contact zones of grass snakes reveal a new Central European snake species. Scientific Reports 7. DOI:10.1038/s41598-017-07847-9.  

Where to find them

Grass snakes are found throughout England and Wales.

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.


This is the UK's longest snake, growing to well over a metre in length. Typically grass snakes are grey-green in colour. They have a distinctive yellow and black collar around the neck, with black bars down the sides of the body.


Grass snakes are Britain’s only egg-laying snake. Females lay eggs in June or July, normally in rotting vegetation (including garden compost heaps) which acts as an incubator. The eggs hatch into miniature versions of the adults in the late summer months.


Grass snakes are protected by law in Great Britain. It is illegal to deliberately kill, injure or sell grass snakes.

Read more about Britain's only egg-laying snake in this leaflet! 

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