It is the longest snake in the UK, reaching lengths of well over a meter when fully grown. Grass snakes have a coloration that is typically grayish-green. They are easily identifiable by the yellow and black collar that is wrapped around the back of the neck as well as the black bars that run down the sides of the body. Grass snakes are the only species of snake in Britain that are known to deposit eggs. During the months of June and July, females will generally deposit their eggs in decomposing plant matter (including garden compost piles), which serves as an incubator. During the later summer months, the eggs develop into juvenile replicas of the adults that laid them.
Grass snakes are common in both England and Wales and can be found in both countries. Grass snakes, which rely on fish and amphibians for the majority of their diet, have been known to swim into garden ponds during the summer months. This behavior is most common in rural or semi-rural areas of the south. Grass snakes don't have poisonous fangs and are quite skittish; when they sense danger, they run away very rapidly. When trapped, they have the ability to fake their own deaths, and when handled too much, they excrete a putrid-smelling substance.