This snake is found in lowland areas of Britain. It is widespread and common in some areas of the south and south east of England, is absent from Scotland and becomes rare in central Wales (2). It is absent from Ireland, where it is said to have been expelled by Saint Patrick (4). Elsewhere it has a wide distribution in continental Europe, from southern Scandinavia to southern Italy, reaching as far east as Lake Baikal. It also occurs in northwestern Africa. Experts currently disagree as to the number of subspecies of the grass snake; British grass snakes belong to the western subspecies Natrix natrix helvetica (2).