Grass snakes are Britain's largest native snake, but face declining populations from habitat loss and persecution. Understanding their ecology and welfare needs supports better garden and countryside management.
Grass snake welfare is primarily threatened by deliberate killing from fear and misidentification (many people mistake them for adders), habitat loss, and the disappearance of the warm compost and manure heaps they need for egg incubation. Individual snakes disturbed or cornered may play dead or produce a foul-smelling musk as defence - these are stress responses indicating significant disturbance. The loss of traditional compost heaps from increasingly manicured gardens removes essential incubation habitat across the landscape. Cats kill significant numbers of grass snakes in garden populations. The welfare of individual grass snakes depends on a wider landscape that provides connected, undisturbed habitat from watercourses to rough grassland to compost or dung heaps.